diff --git a/packages/api/src/pubsub/eth/eth.js b/packages/api/src/pubsub/eth/eth.js
index d538716f..322b19f8 100644
--- a/packages/api/src/pubsub/eth/eth.js
+++ b/packages/api/src/pubsub/eth/eth.js
@@ -15,65 +15,84 @@
 // along with Parity.  If not, see <http://www.gnu.org/licenses/>.
 const PubsubBase = require('../pubsubBase');
 
-const { inAddress, inBlockNumber, inHex, inNumber16, inOptions, inFilter } = require('../../format/input');
-const { outAddress, outBlock, outNumber, outTransaction, outSyncing, outReceipt, outLog } = require('../../format/output');
+const {
+  inAddress,
+  inBlockNumber,
+  inHex,
+  inNumber16,
+  inOptions,
+  inFilter
+} = require('../../format/input');
+const {
+  outAddress,
+  outBlock,
+  outNumber,
+  outTransaction,
+  outSyncing,
+  outReceipt,
+  outLog
+} = require('../../format/output');
 
 class Eth extends PubsubBase {
-  constructor (provider) {
+  constructor(provider) {
     super(provider);
     this._api = 'parity';
   }
 
-  newHeads (callback) {
-    return this.addListener('eth', 'newHeads', callback, null);
+  newHeads(callback) {
+    return this.addListener(
+      'eth',
+      'newHeads',
+      (error, data) => {
+        error ? callback(error) : callback(null, outBlock(data));
+      },
+      null
+    );
   }
 
-  logs (callback) {
+  syncing(callback) {
+    return this.addListener(
+      'eth',
+      'syncing',
+      (error, data) => {
+        error ? callback(error) : callback(null, outSyncing(data));
+      },
+      null
+    );
+  }
+
+  logs(callback) {
     throw Error('not supported yet');
   }
 
   //  eth API
-  protocolVersion (callback) {
+  protocolVersion(callback) {
     return this.addListener(this._api, 'eth_protocolVersion', callback);
   }
 
-  syncing (callback) {
-    return this.addListener(this._api, 'eth_syncing', (error, data) => {
-      error
-        ? callback(error)
-        : callback(null, outSyncing(data));
-    });
-  }
-
-  hashrate (callback) {
+  hashrate(callback) {
     return this.addListener(this._api, 'eth_hashrate', (error, data) => {
-      error
-        ? callback(error)
-        : callback(null, outNumber(data));
+      error ? callback(error) : callback(null, outNumber(data));
     });
   }
 
-  coinbase (callback) {
+  coinbase(callback) {
     return this.addListener(this._api, 'eth_coinbase', (error, data) => {
-      error
-        ? callback(error)
-        : callback(null, outAddress(data));
+      error ? callback(error) : callback(null, outAddress(data));
     });
   }
 
-  mining (callback) {
+  mining(callback) {
     return this.addListener(this._api, 'eth_mining', callback);
   }
 
-  gasPrice (callback) {
+  gasPrice(callback) {
     return this.addListener(this._api, 'eth_gasPrice', (error, data) => {
-      error
-        ? callback(error)
-        : callback(null, outNumber(data));
+      error ? callback(error) : callback(null, outNumber(data));
     });
   }
 
-  accounts (callback) {
+  accounts(callback) {
     return this.addListener(this._api, 'eth_accounts', (error, accounts) => {
       error
         ? callback(error)
@@ -81,147 +100,211 @@ class Eth extends PubsubBase {
     });
   }
 
-  blockNumber (callback) {
+  blockNumber(callback) {
     return this.addListener(this._api, 'eth_blockNumber', (error, data) => {
-      error
-        ? callback(error)
-        : callback(null, outNumber(data));
+      error ? callback(error) : callback(null, outNumber(data));
     });
   }
 
-  getBalance (callback, address, blockNumber = 'latest') {
-    return this.addListener(this._api, 'eth_getBalance', (error, data) => {
-      error
-        ? callback(error)
-        : callback(null, outNumber(data));
-    }, [inAddress(address), inBlockNumber(blockNumber)]);
+  getBalance(callback, address, blockNumber = 'latest') {
+    return this.addListener(
+      this._api,
+      'eth_getBalance',
+      (error, data) => {
+        error ? callback(error) : callback(null, outNumber(data));
+      },
+      [inAddress(address), inBlockNumber(blockNumber)]
+    );
   }
 
-  getStorageAt (callback, address, index = 0, blockNumber = 'latest') {
-    return this.addListener(this._api, 'eth_getStorageAt', callback, [inAddress(address), inNumber16(index), inBlockNumber(blockNumber)]);
+  getStorageAt(callback, address, index = 0, blockNumber = 'latest') {
+    return this.addListener(this._api, 'eth_getStorageAt', callback, [
+      inAddress(address),
+      inNumber16(index),
+      inBlockNumber(blockNumber)
+    ]);
   }
 
-  getBlockByHash (callback, hash, full = false) {
-    return this.addListener(this._api, 'eth_getBlockByHash', (error, data) => {
-      error
-        ? callback(error)
-        : callback(null, outBlock(data));
-    }, [inHex(hash), full]);
+  getBlockByHash(callback, hash, full = false) {
+    return this.addListener(
+      this._api,
+      'eth_getBlockByHash',
+      (error, data) => {
+        error ? callback(error) : callback(null, outBlock(data));
+      },
+      [inHex(hash), full]
+    );
   }
 
-  getBlockByNumber (callback, blockNumber = 'latest', full = false) {
-    return this.addListener(this._api, 'eth_getBlockByNumber', (error, data) => {
-      error
-        ? callback(error)
-        : callback(null, outBlock(data));
-    }, [inBlockNumber(blockNumber), full]);
+  getBlockByNumber(callback, blockNumber = 'latest', full = false) {
+    return this.addListener(
+      this._api,
+      'eth_getBlockByNumber',
+      (error, data) => {
+        error ? callback(error) : callback(null, outBlock(data));
+      },
+      [inBlockNumber(blockNumber), full]
+    );
   }
 
-  getTransactionCount (callback, address, blockNumber = 'latest') {
-    return this.addListener(this._api, 'eth_getTransactionCount', (error, data) => {
-      error
-        ? callback(error)
-        : callback(null, outNumber(data));
-    }, [inAddress(address), inBlockNumber(blockNumber)]);
+  getTransactionCount(callback, address, blockNumber = 'latest') {
+    return this.addListener(
+      this._api,
+      'eth_getTransactionCount',
+      (error, data) => {
+        error ? callback(error) : callback(null, outNumber(data));
+      },
+      [inAddress(address), inBlockNumber(blockNumber)]
+    );
   }
 
-  getBlockTransactionCountByHash (callback, hash) {
-    return this.addListener(this._api, 'eth_getBlockTransactionCountByHash', (error, data) => {
-      error
-        ? callback(error)
-        : callback(null, outNumber(data));
-    }, [inHex(hash)]);
+  getBlockTransactionCountByHash(callback, hash) {
+    return this.addListener(
+      this._api,
+      'eth_getBlockTransactionCountByHash',
+      (error, data) => {
+        error ? callback(error) : callback(null, outNumber(data));
+      },
+      [inHex(hash)]
+    );
   }
 
-  getBlockTransactionCountByNumber (callback, blockNumber = 'latest') {
-    return this.addListener(this._api, 'eth_getBlockTransactionCountByNumber', (error, data) => {
-      error
-        ? callback(error)
-        : callback(null, outNumber(data));
-    }, [inBlockNumber(blockNumber)]);
+  getBlockTransactionCountByNumber(callback, blockNumber = 'latest') {
+    return this.addListener(
+      this._api,
+      'eth_getBlockTransactionCountByNumber',
+      (error, data) => {
+        error ? callback(error) : callback(null, outNumber(data));
+      },
+      [inBlockNumber(blockNumber)]
+    );
   }
 
-  getUncleCountByBlockHash (callback, hash) {
-    return this.addListener(this._api, 'eth_getUncleCountByBlockHash', (error, data) => {
-      error
-        ? callback(error)
-        : callback(null, outNumber(data));
-    }, [inHex(hash)]);
+  getUncleCountByBlockHash(callback, hash) {
+    return this.addListener(
+      this._api,
+      'eth_getUncleCountByBlockHash',
+      (error, data) => {
+        error ? callback(error) : callback(null, outNumber(data));
+      },
+      [inHex(hash)]
+    );
   }
 
-  getUncleCountByBlockNumber (callback, blockNumber = 'latest') {
-    return this.addListener(this._api, 'eth_getUncleCountByBlockNumber', (error, data) => {
-      error
-        ? callback(error)
-        : callback(null, outNumber(data));
-    }, [inBlockNumber(blockNumber)]);
+  getUncleCountByBlockNumber(callback, blockNumber = 'latest') {
+    return this.addListener(
+      this._api,
+      'eth_getUncleCountByBlockNumber',
+      (error, data) => {
+        error ? callback(error) : callback(null, outNumber(data));
+      },
+      [inBlockNumber(blockNumber)]
+    );
   }
 
-  getCode (callback, address, blockNumber = 'latest') {
-    return this.addListener(this._api, 'eth_getCode', callback, [inAddress(address), inBlockNumber(blockNumber)]);
+  getCode(callback, address, blockNumber = 'latest') {
+    return this.addListener(this._api, 'eth_getCode', callback, [
+      inAddress(address),
+      inBlockNumber(blockNumber)
+    ]);
   }
 
-  call (callback, options, blockNumber = 'latest') {
-    return this.addListener(this._api, 'eth_call', callback, [inOptions(options), inBlockNumber(blockNumber)]);
+  call(callback, options, blockNumber = 'latest') {
+    return this.addListener(this._api, 'eth_call', callback, [
+      inOptions(options),
+      inBlockNumber(blockNumber)
+    ]);
   }
 
-  estimateGas (callback, options) {
-    return this.addListener(this._api, 'eth_estimateGas', (error, data) => {
-      error
-        ? callback(error)
-        : callback(null, outNumber(data));
-    }, [inOptions(options)]);
+  estimateGas(callback, options) {
+    return this.addListener(
+      this._api,
+      'eth_estimateGas',
+      (error, data) => {
+        error ? callback(error) : callback(null, outNumber(data));
+      },
+      [inOptions(options)]
+    );
   }
 
-  getTransactionByHash (callback, hash) {
-    return this.addListener(this._api, 'eth_getTransactionByHash', (error, data) => {
-      error
-        ? callback(error)
-        : callback(null, outTransaction(data));
-    }, [inHex(hash)]);
+  getTransactionByHash(callback, hash) {
+    return this.addListener(
+      this._api,
+      'eth_getTransactionByHash',
+      (error, data) => {
+        error ? callback(error) : callback(null, outTransaction(data));
+      },
+      [inHex(hash)]
+    );
   }
 
-  getTransactionByBlockHashAndIndex (callback, hash, index = 0) {
-    return this.addListener(this._api, 'eth_getTransactionByBlockHashAndIndex', (error, data) => {
-      error
-        ? callback(error)
-        : callback(null, outTransaction(data));
-    }, [inHex(hash), inNumber16(index)]);
+  getTransactionByBlockHashAndIndex(callback, hash, index = 0) {
+    return this.addListener(
+      this._api,
+      'eth_getTransactionByBlockHashAndIndex',
+      (error, data) => {
+        error ? callback(error) : callback(null, outTransaction(data));
+      },
+      [inHex(hash), inNumber16(index)]
+    );
   }
 
-  getTransactionByBlockNumberAndIndex (callback, blockNumber = 'latest', index = 0) {
-    return this.addListener(this._api, 'eth_getTransactionByBlockNumberAndIndex', (error, data) => {
-      error
-        ? callback(error)
-        : callback(null, outTransaction(data));
-    }, [inBlockNumber(blockNumber), inNumber16(index)]);
+  getTransactionByBlockNumberAndIndex(
+    callback,
+    blockNumber = 'latest',
+    index = 0
+  ) {
+    return this.addListener(
+      this._api,
+      'eth_getTransactionByBlockNumberAndIndex',
+      (error, data) => {
+        error ? callback(error) : callback(null, outTransaction(data));
+      },
+      [inBlockNumber(blockNumber), inNumber16(index)]
+    );
   }
 
-  getTransactionReceipt (callback, txhash) {
-    return this.addListener(this._api, 'eth_getTransactionReceipt', (error, data) => {
-      error
-        ? callback(error)
-        : callback(null, outReceipt(data));
-    }, [inHex(txhash)]);
+  getTransactionReceipt(callback, txhash) {
+    return this.addListener(
+      this._api,
+      'eth_getTransactionReceipt',
+      (error, data) => {
+        error ? callback(error) : callback(null, outReceipt(data));
+      },
+      [inHex(txhash)]
+    );
   }
 
-  getUncleByBlockHashAndIndex (callback, hash, index = 0) {
-    return this.addListener(this._api, 'eth_getUncleByBlockHashAndIndex', callback, [inHex(hash), inNumber16(index)]);
+  getUncleByBlockHashAndIndex(callback, hash, index = 0) {
+    return this.addListener(
+      this._api,
+      'eth_getUncleByBlockHashAndIndex',
+      callback,
+      [inHex(hash), inNumber16(index)]
+    );
   }
 
-  getUncleByBlockNumberAndIndex (callback, blockNumber = 'latest', index = 0) {
-    return this.addListener(this._api, 'eth_getUncleByBlockNumberAndIndex', callback, [inBlockNumber(blockNumber), inNumber16(index)]);
+  getUncleByBlockNumberAndIndex(callback, blockNumber = 'latest', index = 0) {
+    return this.addListener(
+      this._api,
+      'eth_getUncleByBlockNumberAndIndex',
+      callback,
+      [inBlockNumber(blockNumber), inNumber16(index)]
+    );
   }
 
-  getLogs (callback, options) {
-    return this.addListener(this._api, 'eth_getLogs', (error, logs) => {
-      error
-        ? callback(error)
-        : callback(null, (logs) => logs.map(outLog));
-    }, [inFilter(options)]);
+  getLogs(callback, options) {
+    return this.addListener(
+      this._api,
+      'eth_getLogs',
+      (error, logs) => {
+        error ? callback(error) : callback(null, logs => logs.map(outLog));
+      },
+      [inFilter(options)]
+    );
   }
 
-  getWork (callback) {
+  getWork(callback) {
     return this.addListener(this._api, 'eth_getWork', callback);
   }
 }
diff --git a/packages/api/src/pubsub/pubsub.spec.js b/packages/api/src/pubsub/pubsub.spec.js
index 0d0d0d6d..ddd544a5 100644
--- a/packages/api/src/pubsub/pubsub.spec.js
+++ b/packages/api/src/pubsub/pubsub.spec.js
@@ -30,17 +30,25 @@ describe('pubsub/Pubsub', () => {
 
   describe('accountsInfo', () => {
     beforeEach(() => {
-      scope = mockWs([{ method: 'parity_subscribe', reply: 2, subscription: {
-        method: 'parity_subscription',
-        params: {
-          result: {
-            '0x63cf90d3f0410092fc0fca41846f596223979195': {
-              name: 'name', uuid: 'uuid', meta: '{"data":"data"}'
+      scope = mockWs([
+        {
+          method: 'parity_subscribe',
+          reply: 2,
+          subscription: {
+            method: 'parity_subscription',
+            params: {
+              result: {
+                '0x63cf90d3f0410092fc0fca41846f596223979195': {
+                  name: 'name',
+                  uuid: 'uuid',
+                  meta: '{"data":"data"}'
+                }
+              },
+              subscription: 2
             }
-          },
-          subscription: 2
+          }
         }
-      } }]);
+      ]);
       instance = new Pubsub(new WsSecure(TEST_WS_URL));
     });
 
@@ -48,12 +56,14 @@ describe('pubsub/Pubsub', () => {
       scope.stop();
     });
 
-    it('retrieves the available account info', (done) => {
+    it('retrieves the available account info', done => {
       instance.parity.accountsInfo((error, result) => {
         expect(error).to.be.null;
         expect(result).to.deep.equal({
           '0x63Cf90D3f0410092FC0fca41846f596223979195': {
-            name: 'name', uuid: 'uuid', meta: {
+            name: 'name',
+            uuid: 'uuid',
+            meta: {
               data: 'data'
             }
           }
@@ -76,7 +86,7 @@ describe('pubsub/Pubsub', () => {
       scope.stop();
     });
 
-    it('Promise gets resolved on success.', (done) => {
+    it('Promise gets resolved on success.', done => {
       instance.parity.accountsInfo().then(s => {
         instance.parity.unsubscribe(s).then(b => {
           expect(b).to.be.true;
@@ -88,15 +98,21 @@ describe('pubsub/Pubsub', () => {
 
   describe('chainStatus', () => {
     beforeEach(() => {
-      scope = mockWs([{ method: 'parity_subscribe', reply: 2, subscription: {
-        method: 'parity_subscription',
-        params: {
-          result: {
-            'blockGap': [0x123, 0x456]
-          },
-          subscription: 2
+      scope = mockWs([
+        {
+          method: 'parity_subscribe',
+          reply: 2,
+          subscription: {
+            method: 'parity_subscription',
+            params: {
+              result: {
+                blockGap: [0x123, 0x456]
+              },
+              subscription: 2
+            }
+          }
         }
-      } }]);
+      ]);
       instance = new Pubsub(new WsSecure(TEST_WS_URL));
     });
 
@@ -104,11 +120,11 @@ describe('pubsub/Pubsub', () => {
       scope.stop();
     });
 
-    it('retrieves the chain status', (done) => {
+    it('retrieves the chain status', done => {
       instance.parity.chainStatus((error, result) => {
         expect(error).to.be.null;
         expect(result).to.deep.equal({
-          'blockGap': [new BigNumber(0x123), new BigNumber(0x456)]
+          blockGap: [new BigNumber(0x123), new BigNumber(0x456)]
         });
         done();
       });
@@ -117,13 +133,19 @@ describe('pubsub/Pubsub', () => {
 
   describe('gasFloorTarget', () => {
     beforeEach(() => {
-      scope = mockWs([{ method: 'parity_subscribe', reply: 2, subscription: {
-        method: 'parity_subscription',
-        params: {
-          result: '0x123456',
-          subscription: 2
+      scope = mockWs([
+        {
+          method: 'parity_subscribe',
+          reply: 2,
+          subscription: {
+            method: 'parity_subscription',
+            params: {
+              result: '0x123456',
+              subscription: 2
+            }
+          }
         }
-      } }]);
+      ]);
       instance = new Pubsub(new WsSecure(TEST_WS_URL));
     });
 
@@ -131,7 +153,7 @@ describe('pubsub/Pubsub', () => {
       scope.stop();
     });
 
-    it('returns the gasfloor, formatted', (done) => {
+    it('returns the gasfloor, formatted', done => {
       instance.parity.gasFloorTarget((error, result) => {
         expect(error).to.be.null;
         expect(isBigNumber(result)).to.be.true;
@@ -143,13 +165,19 @@ describe('pubsub/Pubsub', () => {
 
   describe('transactionsLimit', () => {
     beforeEach(() => {
-      scope = mockWs([{ method: 'parity_subscribe', reply: 2, subscription: {
-        method: 'parity_subscription',
-        params: {
-          result: 1024,
-          subscription: 2
+      scope = mockWs([
+        {
+          method: 'parity_subscribe',
+          reply: 2,
+          subscription: {
+            method: 'parity_subscription',
+            params: {
+              result: 1024,
+              subscription: 2
+            }
+          }
         }
-      } }]);
+      ]);
       instance = new Pubsub(new WsSecure(TEST_WS_URL));
     });
 
@@ -157,7 +185,7 @@ describe('pubsub/Pubsub', () => {
       scope.stop();
     });
 
-    it('returns the tx limit, formatted', (done) => {
+    it('returns the tx limit, formatted', done => {
       instance.parity.transactionsLimit((error, result) => {
         expect(error).to.be.null;
         expect(isBigNumber(result)).to.be.true;
@@ -169,13 +197,19 @@ describe('pubsub/Pubsub', () => {
 
   describe('minGasPrice', () => {
     beforeEach(() => {
-      scope = mockWs([{ method: 'parity_subscribe', reply: 2, subscription: {
-        method: 'parity_subscription',
-        params: {
-          result: '0x123456',
-          subscription: 2
+      scope = mockWs([
+        {
+          method: 'parity_subscribe',
+          reply: 2,
+          subscription: {
+            method: 'parity_subscription',
+            params: {
+              result: '0x123456',
+              subscription: 2
+            }
+          }
         }
-      } }]);
+      ]);
       instance = new Pubsub(new WsSecure(TEST_WS_URL));
     });
 
@@ -183,7 +217,7 @@ describe('pubsub/Pubsub', () => {
       scope.stop();
     });
 
-    it('returns the min gasprice, formatted', (done) => {
+    it('returns the min gasprice, formatted', done => {
       instance.parity.minGasPrice((error, result) => {
         expect(error).to.be.null;
         expect(isBigNumber(result)).to.be.true;
@@ -195,13 +229,19 @@ describe('pubsub/Pubsub', () => {
 
   describe('netPeers', () => {
     beforeEach(() => {
-      scope = mockWs([{ method: 'parity_subscribe', reply: 2, subscription: {
-        method: 'parity_subscription',
-        params: {
-          result: { active: 123, connected: 456, max: 789, peers: [] },
-          subscription: 2
+      scope = mockWs([
+        {
+          method: 'parity_subscribe',
+          reply: 2,
+          subscription: {
+            method: 'parity_subscription',
+            params: {
+              result: { active: 123, connected: 456, max: 789, peers: [] },
+              subscription: 2
+            }
+          }
         }
-      } }]);
+      ]);
       instance = new Pubsub(new WsSecure(TEST_WS_URL));
     });
 
@@ -209,7 +249,7 @@ describe('pubsub/Pubsub', () => {
       scope.stop();
     });
 
-    it('returns the peer structure, formatted', (done) => {
+    it('returns the peer structure, formatted', done => {
       instance.parity.netPeers((error, peers) => {
         expect(error).to.be.null;
         expect(peers.active.eq(123)).to.be.true;
@@ -222,13 +262,19 @@ describe('pubsub/Pubsub', () => {
 
   describe('netPort', () => {
     beforeEach(() => {
-      scope = mockWs([{ method: 'parity_subscribe', reply: 2, subscription: {
-        method: 'parity_subscription',
-        params: {
-          result: 33030,
-          subscription: 2
+      scope = mockWs([
+        {
+          method: 'parity_subscribe',
+          reply: 2,
+          subscription: {
+            method: 'parity_subscription',
+            params: {
+              result: 33030,
+              subscription: 2
+            }
+          }
         }
-      } }]);
+      ]);
       instance = new Pubsub(new WsSecure(TEST_WS_URL));
     });
 
@@ -236,7 +282,7 @@ describe('pubsub/Pubsub', () => {
       scope.stop();
     });
 
-    it('returns the connected port, formatted', (done) => {
+    it('returns the connected port, formatted', done => {
       instance.parity.netPort((error, count) => {
         expect(error).to.be.null;
         expect(isBigNumber(count)).to.be.true;
@@ -248,13 +294,19 @@ describe('pubsub/Pubsub', () => {
 
   describe('accounts', () => {
     beforeEach(() => {
-      scope = mockWs([{ method: 'parity_subscribe', reply: 2, subscription: {
-        method: 'parity_subscription',
-        params: {
-          result: [address.toLowerCase()],
-          subscription: 2
+      scope = mockWs([
+        {
+          method: 'parity_subscribe',
+          reply: 2,
+          subscription: {
+            method: 'parity_subscription',
+            params: {
+              result: [address.toLowerCase()],
+              subscription: 2
+            }
+          }
         }
-      } }]);
+      ]);
       instance = new Pubsub(new WsSecure(TEST_WS_URL));
     });
 
@@ -262,7 +314,7 @@ describe('pubsub/Pubsub', () => {
       scope.stop();
     });
 
-    it('returns a list of accounts, formatted', (done) => {
+    it('returns a list of accounts, formatted', done => {
       instance.eth.accounts((error, accounts) => {
         expect(error).to.be.null;
         expect(accounts).to.deep.equal([address]);
@@ -273,13 +325,19 @@ describe('pubsub/Pubsub', () => {
 
   describe('newHeads', () => {
     beforeEach(() => {
-      scope = mockWs([{ method: 'eth_subscribe', reply: 2, subscription: {
-        method: 'eth_subscription',
-        params: {
-          result: '0x123456',
-          subscription: 2
+      scope = mockWs([
+        {
+          method: 'eth_subscribe',
+          reply: 2,
+          subscription: {
+            method: 'eth_subscription',
+            params: {
+              result: '0x123456',
+              subscription: 2
+            }
+          }
         }
-      } }]);
+      ]);
       instance = new Pubsub(new WsSecure(TEST_WS_URL));
     });
 
@@ -287,10 +345,10 @@ describe('pubsub/Pubsub', () => {
       scope.stop();
     });
 
-    it('returns newHeads for eth_subscribe', (done) => {
-      instance.eth.newHeads((error, blockNumber) => {
+    it('returns newHeads for eth_subscribe', done => {
+      instance.eth.newHeads((error, block) => {
         expect(error).to.be.null;
-        expect(blockNumber).to.equal('0x123456');
+        expect(block).not.to.be.null;
         done();
       });
     });
@@ -298,13 +356,19 @@ describe('pubsub/Pubsub', () => {
 
   describe('blockNumber', () => {
     beforeEach(() => {
-      scope = mockWs([{ method: 'parity_subscribe', reply: 2, subscription: {
-        method: 'parity_subscription',
-        params: {
-          result: '0x123456',
-          subscription: 2
+      scope = mockWs([
+        {
+          method: 'parity_subscribe',
+          reply: 2,
+          subscription: {
+            method: 'parity_subscription',
+            params: {
+              result: '0x123456',
+              subscription: 2
+            }
+          }
         }
-      } }]);
+      ]);
       instance = new Pubsub(new WsSecure(TEST_WS_URL));
     });
 
@@ -312,7 +376,7 @@ describe('pubsub/Pubsub', () => {
       scope.stop();
     });
 
-    it('returns the current blockNumber, formatted', (done) => {
+    it('returns the current blockNumber, formatted', done => {
       instance.eth.blockNumber((error, blockNumber) => {
         expect(error).to.be.null;
         expect(isBigNumber(blockNumber)).to.be.true;
@@ -324,13 +388,19 @@ describe('pubsub/Pubsub', () => {
 
   describe('call', () => {
     beforeEach(() => {
-      scope = mockWs([{ method: 'parity_subscribe', reply: 2, subscription: {
-        method: 'parity_subscription',
-        params: {
-          result: [],
-          subscription: 2
+      scope = mockWs([
+        {
+          method: 'parity_subscribe',
+          reply: 2,
+          subscription: {
+            method: 'parity_subscription',
+            params: {
+              result: [],
+              subscription: 2
+            }
+          }
         }
-      } }]);
+      ]);
       instance = new Pubsub(new WsSecure(TEST_WS_URL));
     });
 
@@ -338,32 +408,51 @@ describe('pubsub/Pubsub', () => {
       scope.stop();
     });
 
-    it('formats the input options & blockNumber', (done) => {
-      instance.eth.call((error) => {
-        expect(error).to.be.null;
-        expect(scope.body.parity_subscribe.params).to.deep.equal(['eth_call', [{ data: '0x12345678' }, 'earliest']]);
-        done();
-      }, { data: '12345678' }, 'earliest');
-    });
-
-    it('provides a latest blockNumber when not specified', (done) => {
-      instance.eth.call((error) => {
-        expect(error).to.be.null;
-        expect(scope.body.parity_subscribe.params).to.deep.equal(['eth_call', [{ data: '0x12345678' }, 'latest']]);
-        done();
-      }, { data: '12345678' });
+    it('formats the input options & blockNumber', done => {
+      instance.eth.call(
+        error => {
+          expect(error).to.be.null;
+          expect(scope.body.parity_subscribe.params).to.deep.equal([
+            'eth_call',
+            [{ data: '0x12345678' }, 'earliest']
+          ]);
+          done();
+        },
+        { data: '12345678' },
+        'earliest'
+      );
+    });
+
+    it('provides a latest blockNumber when not specified', done => {
+      instance.eth.call(
+        error => {
+          expect(error).to.be.null;
+          expect(scope.body.parity_subscribe.params).to.deep.equal([
+            'eth_call',
+            [{ data: '0x12345678' }, 'latest']
+          ]);
+          done();
+        },
+        { data: '12345678' }
+      );
     });
   });
 
   describe('coinbase', () => {
     beforeEach(() => {
-      scope = mockWs([{ method: 'parity_subscribe', reply: 2, subscription: {
-        method: 'parity_subscription',
-        params: {
-          result: address.toLowerCase(),
-          subscription: 2
+      scope = mockWs([
+        {
+          method: 'parity_subscribe',
+          reply: 2,
+          subscription: {
+            method: 'parity_subscription',
+            params: {
+              result: address.toLowerCase(),
+              subscription: 2
+            }
+          }
         }
-      } }]);
+      ]);
       instance = new Pubsub(new WsSecure(TEST_WS_URL));
     });
 
@@ -371,7 +460,7 @@ describe('pubsub/Pubsub', () => {
       scope.stop();
     });
 
-    it('returns the coinbase, formatted', (done) => {
+    it('returns the coinbase, formatted', done => {
       instance.eth.coinbase((error, account) => {
         expect(error).to.be.null;
         expect(account).to.deep.equal(address);
@@ -382,13 +471,19 @@ describe('pubsub/Pubsub', () => {
 
   describe('estimateGas', () => {
     beforeEach(() => {
-      scope = mockWs([{ method: 'parity_subscribe', reply: 2, subscription: {
-        method: 'parity_subscription',
-        params: {
-          result: '0x123',
-          subscription: 2
+      scope = mockWs([
+        {
+          method: 'parity_subscribe',
+          reply: 2,
+          subscription: {
+            method: 'parity_subscription',
+            params: {
+              result: '0x123',
+              subscription: 2
+            }
+          }
         }
-      } }]);
+      ]);
       instance = new Pubsub(new WsSecure(TEST_WS_URL));
     });
 
@@ -396,15 +491,21 @@ describe('pubsub/Pubsub', () => {
       scope.stop();
     });
 
-    it('converts the options correctly', (done) => {
-      instance.eth.estimateGas((error) => {
-        expect(error).to.be.null;
-        expect(scope.body.parity_subscribe.params).to.deep.equal(['eth_estimateGas', [{ gas: '0x5208' }]]);
-        done();
-      }, { gas: 21000 });
+    it('converts the options correctly', done => {
+      instance.eth.estimateGas(
+        error => {
+          expect(error).to.be.null;
+          expect(scope.body.parity_subscribe.params).to.deep.equal([
+            'eth_estimateGas',
+            [{ gas: '0x5208' }]
+          ]);
+          done();
+        },
+        { gas: 21000 }
+      );
     });
 
-    it('returns the gas used, formatted', (done) => {
+    it('returns the gas used, formatted', done => {
       instance.eth.estimateGas((error, gas) => {
         expect(error).to.be.null;
         expect(isBigNumber(gas)).to.be.true;
@@ -416,13 +517,19 @@ describe('pubsub/Pubsub', () => {
 
   describe('gasPrice', () => {
     beforeEach(() => {
-      scope = mockWs([{ method: 'parity_subscribe', reply: 2, subscription: {
-        method: 'parity_subscription',
-        params: {
-          result: '0x123',
-          subscription: 2
+      scope = mockWs([
+        {
+          method: 'parity_subscribe',
+          reply: 2,
+          subscription: {
+            method: 'parity_subscription',
+            params: {
+              result: '0x123',
+              subscription: 2
+            }
+          }
         }
-      } }]);
+      ]);
       instance = new Pubsub(new WsSecure(TEST_WS_URL));
     });
 
@@ -430,7 +537,7 @@ describe('pubsub/Pubsub', () => {
       scope.stop();
     });
 
-    it('returns the gas price, formatted', (done) => {
+    it('returns the gas price, formatted', done => {
       instance.eth.gasPrice((error, price) => {
         expect(error).to.be.null;
         expect(isBigNumber(price)).to.be.true;
@@ -442,13 +549,19 @@ describe('pubsub/Pubsub', () => {
 
   describe('getBalance', () => {
     beforeEach(() => {
-      scope = mockWs([{ method: 'parity_subscribe', reply: 2, subscription: {
-        method: 'parity_subscription',
-        params: {
-          result: '0x123',
-          subscription: 2
+      scope = mockWs([
+        {
+          method: 'parity_subscribe',
+          reply: 2,
+          subscription: {
+            method: 'parity_subscription',
+            params: {
+              result: '0x123',
+              subscription: 2
+            }
+          }
         }
-      } }]);
+      ]);
       instance = new Pubsub(new WsSecure(TEST_WS_URL));
     });
 
@@ -456,23 +569,33 @@ describe('pubsub/Pubsub', () => {
       scope.stop();
     });
 
-    it('passes in the address (default blockNumber)', (done) => {
-      instance.eth.getBalance((error) => {
+    it('passes in the address (default blockNumber)', done => {
+      instance.eth.getBalance(error => {
         expect(error).to.be.null;
-        expect(scope.body.parity_subscribe.params).to.deep.equal(['eth_getBalance', [address.toLowerCase(), 'latest']]);
+        expect(scope.body.parity_subscribe.params).to.deep.equal([
+          'eth_getBalance',
+          [address.toLowerCase(), 'latest']
+        ]);
         done();
       }, address);
     });
 
-    it('passes in the address & blockNumber', (done) => {
-      instance.eth.getBalance((error) => {
-        expect(error).to.be.null;
-        expect(scope.body.parity_subscribe.params).to.deep.equal(['eth_getBalance', [address.toLowerCase(), '0x456']]);
-        done();
-      }, address, 0x456);
+    it('passes in the address & blockNumber', done => {
+      instance.eth.getBalance(
+        error => {
+          expect(error).to.be.null;
+          expect(scope.body.parity_subscribe.params).to.deep.equal([
+            'eth_getBalance',
+            [address.toLowerCase(), '0x456']
+          ]);
+          done();
+        },
+        address,
+        0x456
+      );
     });
 
-    it('returns the balance', (done) => {
+    it('returns the balance', done => {
       instance.eth.getBalance((error, balance) => {
         expect(error).to.be.null;
         expect(isBigNumber(balance)).to.be.true;
@@ -484,13 +607,19 @@ describe('pubsub/Pubsub', () => {
 
   describe('getBlockByHash', () => {
     beforeEach(() => {
-      scope = mockWs([{ method: 'parity_subscribe', reply: 2, subscription: {
-        method: 'parity_subscription',
-        params: {
-          result: { miner: address.toLowerCase() },
-          subscription: 2
+      scope = mockWs([
+        {
+          method: 'parity_subscribe',
+          reply: 2,
+          subscription: {
+            method: 'parity_subscription',
+            params: {
+              result: { miner: address.toLowerCase() },
+              subscription: 2
+            }
+          }
         }
-      } }]);
+      ]);
       instance = new Pubsub(new WsSecure(TEST_WS_URL));
     });
 
@@ -498,23 +627,33 @@ describe('pubsub/Pubsub', () => {
       scope.stop();
     });
 
-    it('formats the input hash as a hash, default full', (done) => {
-      instance.eth.getBlockByHash((error) => {
+    it('formats the input hash as a hash, default full', done => {
+      instance.eth.getBlockByHash(error => {
         expect(error).to.be.null;
-        expect(scope.body.parity_subscribe.params).to.deep.equal(['eth_getBlockByHash', ['0x1234', false]]);
+        expect(scope.body.parity_subscribe.params).to.deep.equal([
+          'eth_getBlockByHash',
+          ['0x1234', false]
+        ]);
         done();
       }, '1234');
     });
 
-    it('formats the input hash as a hash, full true', (done) => {
-      instance.eth.getBlockByHash((error) => {
-        expect(error).to.be.null;
-        expect(scope.body.parity_subscribe.params).to.deep.equal(['eth_getBlockByHash', ['0x1234', true]]);
-        done();
-      }, '1234', true);
+    it('formats the input hash as a hash, full true', done => {
+      instance.eth.getBlockByHash(
+        error => {
+          expect(error).to.be.null;
+          expect(scope.body.parity_subscribe.params).to.deep.equal([
+            'eth_getBlockByHash',
+            ['0x1234', true]
+          ]);
+          done();
+        },
+        '1234',
+        true
+      );
     });
 
-    it('formats the output into block', (done) => {
+    it('formats the output into block', done => {
       instance.eth.getBlockByHash((error, block) => {
         expect(error).to.be.null;
         expect(block.miner).to.equal(address);
@@ -525,13 +664,19 @@ describe('pubsub/Pubsub', () => {
 
   describe('getBlockByNumber', () => {
     beforeEach(() => {
-      scope = mockWs([{ method: 'parity_subscribe', reply: 2, subscription: {
-        method: 'parity_subscription',
-        params: {
-          result: { miner: address.toLowerCase() },
-          subscription: 2
+      scope = mockWs([
+        {
+          method: 'parity_subscribe',
+          reply: 2,
+          subscription: {
+            method: 'parity_subscription',
+            params: {
+              result: { miner: address.toLowerCase() },
+              subscription: 2
+            }
+          }
         }
-      } }]);
+      ]);
       instance = new Pubsub(new WsSecure(TEST_WS_URL));
     });
 
@@ -539,31 +684,44 @@ describe('pubsub/Pubsub', () => {
       scope.stop();
     });
 
-    it('assumes blockNumber latest & full false', (done) => {
-      instance.eth.getBlockByNumber((error) => {
+    it('assumes blockNumber latest & full false', done => {
+      instance.eth.getBlockByNumber(error => {
         expect(error).to.be.null;
-        expect(scope.body.parity_subscribe.params).to.deep.equal(['eth_getBlockByNumber', ['latest', false]]);
+        expect(scope.body.parity_subscribe.params).to.deep.equal([
+          'eth_getBlockByNumber',
+          ['latest', false]
+        ]);
         done();
       });
     });
 
-    it('uses input blockNumber & full false', (done) => {
-      instance.eth.getBlockByNumber((error) => {
+    it('uses input blockNumber & full false', done => {
+      instance.eth.getBlockByNumber(error => {
         expect(error).to.be.null;
-        expect(scope.body.parity_subscribe.params).to.deep.equal(['eth_getBlockByNumber', ['0x1234', false]]);
+        expect(scope.body.parity_subscribe.params).to.deep.equal([
+          'eth_getBlockByNumber',
+          ['0x1234', false]
+        ]);
         done();
       }, '0x1234');
     });
 
-    it('formats the input blockNumber, full true', (done) => {
-      instance.eth.getBlockByNumber((error) => {
-        expect(error).to.be.null;
-        expect(scope.body.parity_subscribe.params).to.deep.equal(['eth_getBlockByNumber', ['0x1234', true]]);
-        done();
-      }, 0x1234, true);
+    it('formats the input blockNumber, full true', done => {
+      instance.eth.getBlockByNumber(
+        error => {
+          expect(error).to.be.null;
+          expect(scope.body.parity_subscribe.params).to.deep.equal([
+            'eth_getBlockByNumber',
+            ['0x1234', true]
+          ]);
+          done();
+        },
+        0x1234,
+        true
+      );
     });
 
-    it('formats the output into block', (done) => {
+    it('formats the output into block', done => {
       instance.eth.getBlockByNumber((error, block) => {
         expect(error).to.be.null;
         expect(block.miner).to.equal(address);
@@ -574,13 +732,19 @@ describe('pubsub/Pubsub', () => {
 
   describe('getTransactionCount', () => {
     beforeEach(() => {
-      scope = mockWs([{ method: 'parity_subscribe', reply: 2, subscription: {
-        method: 'parity_subscription',
-        params: {
-          result: '0x123',
-          subscription: 2
+      scope = mockWs([
+        {
+          method: 'parity_subscribe',
+          reply: 2,
+          subscription: {
+            method: 'parity_subscription',
+            params: {
+              result: '0x123',
+              subscription: 2
+            }
+          }
         }
-      } }]);
+      ]);
       instance = new Pubsub(new WsSecure(TEST_WS_URL));
     });
 
@@ -588,29 +752,43 @@ describe('pubsub/Pubsub', () => {
       scope.stop();
     });
 
-    it('passes in the address (default blockNumber)', (done) => {
-      instance.eth.getTransactionCount((error) => {
+    it('passes in the address (default blockNumber)', done => {
+      instance.eth.getTransactionCount(error => {
         expect(error).to.be.null;
-        expect(scope.body.parity_subscribe.params).to.deep.equal(['eth_getTransactionCount', [address.toLowerCase(), 'latest']]);
+        expect(scope.body.parity_subscribe.params).to.deep.equal([
+          'eth_getTransactionCount',
+          [address.toLowerCase(), 'latest']
+        ]);
         done();
       }, address);
     });
 
-    it('passes in the address & blockNumber', (done) => {
-      instance.eth.getTransactionCount((error) => {
-        expect(error).to.be.null;
-        expect(scope.body.parity_subscribe.params).to.deep.equal(['eth_getTransactionCount', [address.toLowerCase(), '0x456']]);
-        done();
-      }, address, 0x456);
-    });
-
-    it('returns the count, formatted', (done) => {
-      instance.eth.getTransactionCount((error, count) => {
-        expect(error).to.be.null;
-        expect(isBigNumber(count)).to.be.true;
-        expect(count.toString(16)).to.equal('123');
-        done();
-      }, address, 0x456);
+    it('passes in the address & blockNumber', done => {
+      instance.eth.getTransactionCount(
+        error => {
+          expect(error).to.be.null;
+          expect(scope.body.parity_subscribe.params).to.deep.equal([
+            'eth_getTransactionCount',
+            [address.toLowerCase(), '0x456']
+          ]);
+          done();
+        },
+        address,
+        0x456
+      );
+    });
+
+    it('returns the count, formatted', done => {
+      instance.eth.getTransactionCount(
+        (error, count) => {
+          expect(error).to.be.null;
+          expect(isBigNumber(count)).to.be.true;
+          expect(count.toString(16)).to.equal('123');
+          done();
+        },
+        address,
+        0x456
+      );
     });
   });
 });
diff --git a/packages/api/src/transport/ws/ws.js b/packages/api/src/transport/ws/ws.js
index 26091f08..08cde330 100644
--- a/packages/api/src/transport/ws/ws.js
+++ b/packages/api/src/transport/ws/ws.js
@@ -212,11 +212,11 @@ class Ws extends JsonRpcBase {
   }
 
   _extract (result) {
-    const { result: res, id, method, params } = result;
+    const { result: res, error, id, method, params } = result;
     const msg = this._messages[id];
 
     // initial pubsub ACK
-    if (id && msg.subscription) {
+    if (id && msg.subscription && !error) {
       // save subscription to map subId -> messageId
       this._subscriptions[msg.subscription] = this._subscriptions[msg.subscription] || {};
       this._subscriptions[msg.subscription][res] = id;
diff --git a/packages/light.js/example/src/provider.js b/packages/light.js/example/src/provider.js
index 58cc4564..3e5ff4d3 100644
--- a/packages/light.js/example/src/provider.js
+++ b/packages/light.js/example/src/provider.js
@@ -7,6 +7,9 @@ import Api from '@parity/api';
 
 export const currentProvider = window.web3 && window.web3.currentProvider;
 export const localProvider = new Api.Provider.Ws('ws://127.0.0.1:8546');
+export const infuraProvider = new Api.Provider.Ws(
+  'wss://mainnet.infura.io/_ws'
+);
 
 const provider = currentProvider || localProvider;
 
diff --git a/packages/light.js/src/api.ts b/packages/light.js/src/api.ts
index 429a2d3d..f0d7b7c6 100644
--- a/packages/light.js/src/api.ts
+++ b/packages/light.js/src/api.ts
@@ -25,11 +25,6 @@ export const createApiFromProvider = memoizee(
  */
 export const setApi = (newApi: any) => {
   api = newApi;
-  if (!api.isPubSub) {
-    console.warn(
-      `Current provider does not support pubsub. @parity/light.js will poll every second to listen to changes.`
-    );
-  }
 };
 
 /**
diff --git a/packages/light.js/src/frequency/accounts.ts b/packages/light.js/src/frequency/accounts.ts
index e92e15a2..7a0ef515 100644
--- a/packages/light.js/src/frequency/accounts.ts
+++ b/packages/light.js/src/frequency/accounts.ts
@@ -12,7 +12,11 @@ import createPubsubObservable from './utils/createPubsubObservable';
  * @param options - Options to pass to {@link FrequencyObservable}.
  */
 export function onAccountsChanged$ (options?: FrequencyObservableOptions) {
-  return createPubsubObservable<Address[]>('eth_accounts', options);
+  return createPubsubObservable<Address[]>(
+    'eth_accounts',
+    'eth_accounts',
+    options
+  );
 }
 
 /**
@@ -21,5 +25,9 @@ export function onAccountsChanged$ (options?: FrequencyObservableOptions) {
  * @param options - Options to pass to {@link FrequencyObservable}.
  */
 export function onAccountsInfoChanged$ (options?: FrequencyObservableOptions) {
-  return createPubsubObservable<AccountsInfo>('parity_accountsInfo', options);
+  return createPubsubObservable<AccountsInfo>(
+    'parity_accountsInfo',
+    'parity_accountsInfo',
+    options
+  );
 }
diff --git a/packages/light.js/src/frequency/blocks.ts b/packages/light.js/src/frequency/blocks.ts
index 11b2fe53..8481f0c7 100644
--- a/packages/light.js/src/frequency/blocks.ts
+++ b/packages/light.js/src/frequency/blocks.ts
@@ -3,14 +3,14 @@
 //
 // SPDX-License-Identifier: MIT
 
-import BigNumber from 'bignumber.js';
-import { filter, map, withLatestFrom } from 'rxjs/operators';
+import { filter, map, startWith, withLatestFrom } from 'rxjs/operators';
 import * as memoizee from 'memoizee';
 import { Observable } from 'rxjs';
 
+import { Block, FrequencyObservableOptions } from '../types';
 import { createApiFromProvider, getApi } from '../api';
 import createPubsubObservable from './utils/createPubsubObservable';
-import { FrequencyObservableOptions } from '../types';
+import { distinctValues } from '../utils/operators';
 import { onSyncingChanged$ } from './health';
 
 /**
@@ -20,11 +20,16 @@ import { onSyncingChanged$ } from './health';
  */
 const onEveryBlockWithApi$ = memoizee(
   (api: any, options?: FrequencyObservableOptions) =>
-    createPubsubObservable('eth_blockNumber', options).pipe(
-      withLatestFrom(onSyncingChanged$(options)),
+    createPubsubObservable(
+      'eth_newHeads',
+      'eth_getBlockByNumber',
+      options
+    ).pipe(
+      withLatestFrom(onSyncingChanged$(options).pipe(startWith(false))),
       filter(([_, isSyncing]) => isSyncing === false),
-      map(([blockNumber]) => blockNumber)
-    ) as Observable<BigNumber>,
+      map(([blockNumber]) => blockNumber),
+      distinctValues()
+    ) as Observable<Block>,
   { length: 1 } // Only memoize by api
 );
 
diff --git a/packages/light.js/src/frequency/health.ts b/packages/light.js/src/frequency/health.ts
index 4c6d424e..1e2b0613 100644
--- a/packages/light.js/src/frequency/health.ts
+++ b/packages/light.js/src/frequency/health.ts
@@ -17,5 +17,9 @@ import { FrequencyObservableOptions } from '../types';
  * @param options - Options to pass to {@link FrequencyObservable}.
  */
 export function onSyncingChanged$ (options?: FrequencyObservableOptions) {
-  return createPubsubObservable<object | false>('eth_syncing', options);
+  return createPubsubObservable<object | false>(
+    'eth_syncing',
+    'eth_syncing',
+    options
+  );
 }
diff --git a/packages/light.js/src/frequency/utils/createPubsubObservable.spec.ts b/packages/light.js/src/frequency/utils/createPubsubObservable.spec.ts
index 394fcefd..e3f7059a 100644
--- a/packages/light.js/src/frequency/utils/createPubsubObservable.spec.ts
+++ b/packages/light.js/src/frequency/utils/createPubsubObservable.spec.ts
@@ -10,37 +10,49 @@ import { setApi } from '../../api';
 
 it('should return an Observable', () => {
   setApi(resolveApi());
-  expect(isObservable(createPubsubObservable('fake_method'))).toBe(true);
+  expect(
+    isObservable(createPubsubObservable('eth_blockNumber', 'eth_blockNumber'))
+  ).toBe(true);
 });
 
 it('should fire an event when pubsub publishes', done => {
   setApi(resolveApi());
-  createPubsubObservable('fake_method').subscribe(data => {
-    expect(data).toBe('foo');
-    done();
-  });
+  createPubsubObservable('eth_blockNumber', 'eth_blockNumber').subscribe(
+    data => {
+      expect(data).toBe('foo');
+      done();
+    }
+  );
 });
 
 it('should fire an error when pubsub errors', done => {
   setApi(rejectApi());
-  createPubsubObservable('fake_method').subscribe(undefined, err => {
-    expect(err).toEqual(new Error('bar'));
-    done();
-  });
+  createPubsubObservable('eth_blockNumber', 'eth_blockNumber').subscribe(
+    undefined,
+    err => {
+      expect(err).toEqual(new Error('bar'));
+      done();
+    }
+  );
 });
 
 it('should fire an event when polling pubsub publishes', done => {
   setApi(resolveApi('foo', false));
-  createPubsubObservable('fake_method').subscribe(data => {
-    expect(data).toBe('foo');
-    done();
-  });
+  createPubsubObservable('eth_blockNumber', 'eth_blockNumber').subscribe(
+    data => {
+      expect(data).toBe('foo');
+      done();
+    }
+  );
 });
 
 it('should fire an error when polling pubsub errors', done => {
   setApi(rejectApi(new Error('bar'), false));
-  createPubsubObservable('fake_method').subscribe(undefined, err => {
-    expect(err).toEqual(new Error('bar'));
-    done();
-  });
+  createPubsubObservable('eth_blockNumber', 'eth_blockNumber').subscribe(
+    undefined,
+    err => {
+      expect(err).toEqual(new Error('bar'));
+      done();
+    }
+  );
 });
diff --git a/packages/light.js/src/frequency/utils/createPubsubObservable.ts b/packages/light.js/src/frequency/utils/createPubsubObservable.ts
index 9534ace3..be454ba4 100644
--- a/packages/light.js/src/frequency/utils/createPubsubObservable.ts
+++ b/packages/light.js/src/frequency/utils/createPubsubObservable.ts
@@ -4,22 +4,45 @@
 // SPDX-License-Identifier: MIT
 
 import * as debug from 'debug';
+import { exhaustMap } from 'rxjs/operators';
 import { FrequencyObservableOptions } from '../../types';
 import * as memoizee from 'memoizee';
 import { Observable, Observer, timer } from 'rxjs';
-import { switchMap } from 'rxjs/operators';
 
 import { createApiFromProvider, getApi } from '../../api';
 import { distinctReplayRefCount } from '../../utils/operators/distinctReplayRefCount';
 
+const POLL_INTERVAL = 1000;
+
+/**
+ * Create a polling function, calls the `fallback` JSONRPC on each second, or
+ * on previous call's result, whichever comes last.
+ *
+ * @ignore
+ */
+function createPoll<T> (
+  fallback: string,
+  api: any,
+  pollInterval = POLL_INTERVAL
+) {
+  const [fallbackNamespace, fallbackMethod] = fallback.split('_');
+
+  return timer(0, pollInterval).pipe(
+    exhaustMap(() => api[fallbackNamespace][fallbackMethod]())
+  ) as Observable<T>;
+}
+
 /**
  * Given an api, returns an Observable that emits on each pubsub event.
  * Pure function version of {@link createPubsubObservable}.
  *
  * @ignore
+ * @param pubsub - The pubsub method to subscribe to.
+ * @param fallback - If pubsub doesn't work, poll this method every
+ * POLL_INTERVAL ms.
  */
 const createPubsubObservableWithApi = memoizee(
-  <T>(pubsub: string, api: any) => {
+  <T>(pubsub: string, fallback: string, api: any) => {
     const [namespace, method] = pubsub.split('_');
 
     // There's a chance the provider doesn't support pubsub, for example
@@ -29,12 +52,10 @@ const createPubsubObservableWithApi = memoizee(
       debug('@parity/light.js:api')(
         `Pubsub not available for ${
           api.provider ? api.provider.constructor.name : 'current Api'
-        } provider, polling "${pubsub}" every second.`
+        } provider, polling "${fallback}" every ${POLL_INTERVAL}ms.`
       );
 
-      return timer(0, 1000).pipe(
-        switchMap(() => api[namespace][method]())
-      ) as Observable<T>;
+      return createPoll<T>(fallback, api);
     }
 
     return Observable.create((observer: Observer<T>) => {
@@ -47,10 +68,25 @@ const createPubsubObservableWithApi = memoizee(
             observer.next(result);
           }
         }
-      );
+      ).catch(() => {
+        // If we get an error during subscription, then default to fallback.
+        // TODO Should this be done on @parity/api?
+        debug('@parity/light.js:api')(
+          `Pubsub not available for method "${pubsub}", polling "${fallback}" every ${POLL_INTERVAL}ms`
+        );
+
+        createPoll<T>(fallback, api).subscribe(
+          e => observer.next(e),
+          e => observer.error(e),
+          () => observer.complete()
+        );
+      });
+
       return () =>
         subscription.then((subscriptionId: string) =>
-          api.pubsub.unsubscribe(subscriptionId)
+          subscriptionId
+            ? api.pubsub.unsubscribe(subscriptionId)
+            : Promise.resolve()
         );
     }).pipe(distinctReplayRefCount()) as Observable<T>;
   }
@@ -64,11 +100,12 @@ const createPubsubObservableWithApi = memoizee(
  */
 const createPubsubObservable = <T>(
   pubsub: string,
+  fallback: string,
   { provider }: FrequencyObservableOptions = {}
 ) => {
   const api = provider ? createApiFromProvider(provider) : getApi();
 
-  return createPubsubObservableWithApi<T>(pubsub, api);
+  return createPubsubObservableWithApi<T>(pubsub, fallback, api);
 };
 
 export default createPubsubObservable;
diff --git a/packages/light.js/src/rpc/eth.ts b/packages/light.js/src/rpc/eth.ts
index 6e6205ae..9e982f4f 100644
--- a/packages/light.js/src/rpc/eth.ts
+++ b/packages/light.js/src/rpc/eth.ts
@@ -7,7 +7,7 @@ import BigNumber from 'bignumber.js';
 import { of } from 'rxjs';
 import { map, switchMap } from 'rxjs/operators';
 
-import { Address, RpcObservableOptions } from '../types';
+import { Address, Block, RpcObservableOptions } from '../types';
 import createRpc$ from './utils/createRpc';
 import frequency from '../frequency';
 import { isNullOrLoading, RPC_LOADING } from '../utils/isLoading';
@@ -66,9 +66,10 @@ export function defaultAccount$ (options?: RpcObservableOptions) {
  * @return {Observable<Number>} - An Observable containing the block height.
  */
 export function blockNumber$ (options?: RpcObservableOptions) {
-  return createRpc$<BigNumber, BigNumber>({
+  return createRpc$<Block, BigNumber>({
     frequency: [frequency.onEveryBlock$],
-    name: 'blockNumber$'
+    name: 'blockNumber$',
+    pipes: () => [map(block => block.number)]
   })(options)();
 }
 
@@ -81,11 +82,10 @@ export function myBalance$ (options?: RpcObservableOptions) {
     dependsOn: defaultAccount$,
     name: 'myBalance$',
     pipes: () => [
-      switchMap(
-        defaultAccount =>
-          isNullOrLoading(defaultAccount)
-            ? of(RPC_LOADING)
-            : balanceOf$(defaultAccount)
+      switchMap(defaultAccount =>
+        isNullOrLoading(defaultAccount)
+          ? of(RPC_LOADING)
+          : balanceOf$(defaultAccount)
       )
     ]
   })(options)();
diff --git a/packages/light.js/src/types.ts b/packages/light.js/src/types.ts
index 9ed40090..b790a581 100644
--- a/packages/light.js/src/types.ts
+++ b/packages/light.js/src/types.ts
@@ -26,6 +26,11 @@ export type Address = string;
 // TODO This should be on @parity/api
 export type ApiValue = any;
 
+// TODO This should be on @parity/api
+export type Block = {
+  number: BigNumber;
+};
+
 export interface Metadata<Source, Out> {
   calledWithArgs?: {
     [key: string]: ReplaySubject<Out>;
diff --git a/packages/light.js/src/utils/operators/distinctValues.spec.ts b/packages/light.js/src/utils/operators/distinctValues.spec.ts
index cf1c6416..6ac63171 100644
--- a/packages/light.js/src/utils/operators/distinctValues.spec.ts
+++ b/packages/light.js/src/utils/operators/distinctValues.spec.ts
@@ -52,3 +52,4 @@ testValue(2, 'number');
 testValue('foo', 'string');
 testValue({ foo: 'bar' }, 'object');
 testValue(new BigNumber(2), 'BigNumber');
+testValue({ number: new BigNumber(2) }, 'Block');
diff --git a/packages/light.js/src/utils/operators/distinctValues.ts b/packages/light.js/src/utils/operators/distinctValues.ts
index f666293b..c909c2da 100644
--- a/packages/light.js/src/utils/operators/distinctValues.ts
+++ b/packages/light.js/src/utils/operators/distinctValues.ts
@@ -7,6 +7,8 @@ import BigNumber from 'bignumber.js';
 import { distinctUntilChanged } from 'rxjs/operators';
 import { isObject } from '@parity/api/lib/util/types';
 
+import { Block } from '../../types';
+
 /**
  * An intelligent distinctUntilChanged().
  *
@@ -14,11 +16,28 @@ import { isObject } from '@parity/api/lib/util/types';
  */
 export const distinctValues = <T>() =>
   distinctUntilChanged<T>((x, y) => {
+    // If T == Block
+    if (
+      x &&
+      y &&
+      ((x as unknown) as Block).number &&
+      ((y as unknown) as Block).number
+    ) {
+      return ((x as unknown) as Block).number.eq(
+        ((y as unknown) as Block).number
+      );
+    }
+
+    // If T == BigNumber
     if (BigNumber.isBigNumber(x) && BigNumber.isBigNumber(y)) {
-      return ((x as any) as BigNumber).eq((y as any) as BigNumber);
+      return ((x as unknown) as BigNumber).eq((y as unknown) as BigNumber);
     }
+
+    // If T == object
     if (isObject(x) && isObject(y)) {
       return JSON.stringify(x) === JSON.stringify(y); // TODO Do a deep equal instead
     }
+
+    // Other cases
     return x === y;
   });
diff --git a/packages/light.js/src/utils/testHelpers/mockApi.ts b/packages/light.js/src/utils/testHelpers/mockApi.ts
index 430c788b..79583d36 100644
--- a/packages/light.js/src/utils/testHelpers/mockApi.ts
+++ b/packages/light.js/src/utils/testHelpers/mockApi.ts
@@ -22,7 +22,7 @@ export class MockProvider extends EventEmitter {
 
 // List of JSONRPCs we want to mock
 const listOfMockRps: { [index: string]: string[] } = {
-  eth: ['accounts', 'blockNumber', 'getBalance', 'syncing'],
+  eth: ['accounts', 'blockNumber', 'getBalance', 'newHeads', 'syncing'],
   fake: ['method'],
   net: ['peerCount'],
   parity: ['accountsInfo', 'chain', 'postTransaction']