diff --git a/README.md b/README.md
index 57e9aad..ee211ce 100644
--- a/README.md
+++ b/README.md
@@ -39,6 +39,16 @@ c.genesis().hash // 0x41941023680923e0fe4d74a34bdac8141f2540e3ae90623718e47d66d1
 c.bootstrapNodes() // Array with current nodes
 ```
 
+It is encouraged to also explicitly set the ``supportedHardforks`` if the initializing library
+only supports a certain range of ``hardforks``:
+
+```javascript
+let c = new Common('ropsten', null, ['byzantium', 'constantinople'])
+```
+
+This will e.g. throw an error when a param is requested for an unsupported hardfork and
+like this prevents unpredicted behaviour.
+
 # API
 
 See the API documentation for a full list of functions for accessing specific chain and
diff --git a/docs/index.md b/docs/index.md
index 09e87d7..ca50137 100644
--- a/docs/index.md
+++ b/docs/index.md
@@ -7,22 +7,23 @@
     -   [setHardfork][3]
     -   [\_chooseHardfork][4]
     -   [\_getHardfork][5]
-    -   [param][6]
-    -   [paramByBlock][7]
-    -   [hardforkIsActiveOnBlock][8]
-    -   [hardforkIsActiveOnChain][9]
-    -   [activeHardforks][10]
-    -   [hardforkBlock][11]
-    -   [isHardforkBlock][12]
-    -   [consensus][13]
-    -   [finality][14]
-    -   [genesis][15]
-    -   [hardforks][16]
-    -   [bootstrapNodes][17]
-    -   [hardfork][18]
-    -   [chainId][19]
-    -   [chainName][20]
-    -   [networkId][21]
+    -   [\_isSupportedHardfork][6]
+    -   [param][7]
+    -   [paramByBlock][8]
+    -   [hardforkIsActiveOnBlock][9]
+    -   [hardforkIsActiveOnChain][10]
+    -   [activeHardforks][11]
+    -   [hardforkBlock][12]
+    -   [isHardforkBlock][13]
+    -   [consensus][14]
+    -   [finality][15]
+    -   [genesis][16]
+    -   [hardforks][17]
+    -   [bootstrapNodes][18]
+    -   [hardfork][19]
+    -   [chainId][20]
+    -   [chainName][21]
+    -   [networkId][22]
 
 ## Common
 
@@ -30,8 +31,9 @@ Common class to access chain and hardfork parameters
 
 **Parameters**
 
--   `chain` **([String][22] \| [Number][23])** String ('mainnet') or Number (1) chain representation
--   `hardfork` **[String][22]** String identifier ('byzantium') for hardfork (optional)
+-   `chain` **([String][23] \| [Number][24])** String ('mainnet') or Number (1) chain representation
+-   `hardfork` **[String][23]** String identifier ('byzantium') for hardfork (optional)
+-   `supportedHardforks` **[Array][25]** Limit parameter returns to the given hardforks (optional)
 
 ### setChain
 
@@ -39,7 +41,7 @@ Sets the chain
 
 **Parameters**
 
--   `chain` **([String][22] \| [Number][23])** String ('mainnet') or Number (1) chain representation
+-   `chain` **([String][23] \| [Number][24])** String ('mainnet') or Number (1) chain representation
 
 ### setHardfork
 
@@ -47,7 +49,7 @@ Sets the hardfork to get params for
 
 **Parameters**
 
--   `hardfork` **[String][22]** String identifier ('byzantium')
+-   `hardfork` **[String][23]** String identifier ('byzantium')
 
 ### \_chooseHardfork
 
@@ -55,9 +57,9 @@ Internal helper function to choose between hardfork set and hardfork provided as
 
 **Parameters**
 
--   `hardfork` **[String][22]** Hardfork given to function as a parameter
+-   `hardfork` **[String][23]** Hardfork given to function as a parameter
 
-Returns **[String][22]** Hardfork chosen to be used
+Returns **[String][23]** Hardfork chosen to be used
 
 ### \_getHardfork
 
@@ -65,19 +67,29 @@ Internal helper function, returns the params for the given hardfork for the chai
 
 **Parameters**
 
--   `hardfork` **[String][22]** Hardfork name
+-   `hardfork` **[String][23]** Hardfork name
 
 Returns **Dictionary** 
 
+### \_isSupportedHardfork
+
+Internal helper function to check if a hardfork is set to be supported by the library
+
+**Parameters**
+
+-   `hardfork` **[String][23]** Hardfork name
+
+Returns **[Boolean][26]** True if hardfork is supported
+
 ### param
 
 Returns the parameter corresponding to a hardfork
 
 **Parameters**
 
--   `topic` **[String][22]** Parameter topic ('gasConfig', 'gasPrices', 'vm', 'pow', 'casper', 'sharding')
--   `name` **[String][22]** Parameter name (e.g. 'minGasLimit' for 'gasConfig' topic)
--   `hardfork` **[String][22]** Hardfork name, optional if hardfork set
+-   `topic` **[String][23]** Parameter topic ('gasConfig', 'gasPrices', 'vm', 'pow', 'casper', 'sharding')
+-   `name` **[String][23]** Parameter name (e.g. 'minGasLimit' for 'gasConfig' topic)
+-   `hardfork` **[String][23]** Hardfork name, optional if hardfork set
 
 ### paramByBlock
 
@@ -85,9 +97,9 @@ Returns a parameter for the hardfork active on block number
 
 **Parameters**
 
--   `topic` **[String][22]** Parameter topic
--   `name` **[String][22]** Parameter name
--   `blockNumber` **[Number][23]** Block number
+-   `topic` **[String][23]** Parameter topic
+-   `name` **[String][23]** Parameter name
+-   `blockNumber` **[Number][24]** Block number
 
 ### hardforkIsActiveOnBlock
 
@@ -95,10 +107,12 @@ Checks if a hardfork is active for a given block number
 
 **Parameters**
 
--   `hardfork` **[String][22]** Hardfork name
--   `blockNumber` **[Number][23]** 
+-   `hardfork` **[String][23]** Hardfork name
+-   `blockNumber` **[Number][24]** 
+-   `opts` **[Array][25]** 
+    -   `opts.onlySupported` **Array.Boolean** optional, only allow supported HFs (default: false)
 
-Returns **[Boolean][24]** 
+Returns **[Boolean][26]** 
 
 ### hardforkIsActiveOnChain
 
@@ -106,9 +120,11 @@ Checks if the hardfork provided is active on the chain
 
 **Parameters**
 
--   `hardfork` **[String][22]** 
+-   `hardfork` **[String][23]** 
+-   `opts` **[Array][25]** 
+    -   `opts.onlySupported` **Array.Boolean** optional, only allow supported HFs (default: false)
 
-Returns **[Boolean][24]** 
+Returns **[Boolean][26]** 
 
 ### activeHardforks
 
@@ -116,7 +132,9 @@ Returns the active hardfork switches for the current chain
 
 **Parameters**
 
--   `blockNumber` **[Number][23]** up to block if provided, otherwise for the whole chain
+-   `blockNumber` **[Number][24]** up to block if provided, otherwise for the whole chain
+-   `opts` **[Array][25]** 
+    -   `opts.onlySupported` **Array.Boolean** optional, limit results to supported HFs (default: false)
 
 Returns **[Array][25]** Array with hardfork arrays
 
@@ -126,9 +144,9 @@ Returns the hardfork change block for the given hardfork
 
 **Parameters**
 
--   `hardfork` **[String][22]** Hardfork name
+-   `hardfork` **[String][23]** Hardfork name
 
-Returns **[Number][23]** Block number
+Returns **[Number][24]** Block number
 
 ### isHardforkBlock
 
@@ -136,10 +154,10 @@ True if block number provided is the hardfork change block of the current chain
 
 **Parameters**
 
--   `hardfork` **[String][22]** Hardfork name
--   `blockNumber` **[Number][23]** Number of the block to check
+-   `hardfork` **[String][23]** Hardfork name
+-   `blockNumber` **[Number][24]** Number of the block to check
 
-Returns **[Boolean][24]** 
+Returns **[Boolean][26]** 
 
 ### consensus
 
@@ -147,9 +165,9 @@ Provide the consensus type for the hardfork set or provided as param
 
 **Parameters**
 
--   `hardfork` **[String][22]** Hardfork name, optional if hardfork set
+-   `hardfork` **[String][23]** Hardfork name, optional if hardfork set
 
-Returns **[String][22]** Consensus type (e.g. 'pow', 'poa')
+Returns **[String][23]** Consensus type (e.g. 'pow', 'poa')
 
 ### finality
 
@@ -157,9 +175,9 @@ Provide the finality type for the hardfork set or provided as param
 
 **Parameters**
 
--   `hardfork` **[String][22]** Hardfork name, optional if hardfork set
+-   `hardfork` **[String][23]** Hardfork name, optional if hardfork set
 
-Returns **[String][22]** Finality type (e.g. 'pos', null of no finality)
+Returns **[String][23]** Finality type (e.g. 'pos', null of no finality)
 
 ### genesis
 
@@ -183,25 +201,25 @@ Returns **Dictionary** Dict with bootstrap nodes
 
 Returns the hardfork set
 
-Returns **[String][22]** Hardfork name
+Returns **[String][23]** Hardfork name
 
 ### chainId
 
 Returns the Id of current chain
 
-Returns **[Number][23]** chain Id
+Returns **[Number][24]** chain Id
 
 ### chainName
 
 Returns the name of current chain
 
-Returns **[String][22]** chain name (lower case)
+Returns **[String][23]** chain name (lower case)
 
 ### networkId
 
 Returns the Id of current network
 
-Returns **[Number][23]** network Id
+Returns **[Number][24]** network Id
 
 [1]: #common
 
@@ -213,42 +231,44 @@ Returns **[Number][23]** network Id
 
 [5]: #_gethardfork
 
-[6]: #param
+[6]: #_issupportedhardfork
 
-[7]: #parambyblock
+[7]: #param
 
-[8]: #hardforkisactiveonblock
+[8]: #parambyblock
 
-[9]: #hardforkisactiveonchain
+[9]: #hardforkisactiveonblock
 
-[10]: #activehardforks
+[10]: #hardforkisactiveonchain
 
-[11]: #hardforkblock
+[11]: #activehardforks
 
-[12]: #ishardforkblock
+[12]: #hardforkblock
 
-[13]: #consensus
+[13]: #ishardforkblock
 
-[14]: #finality
+[14]: #consensus
 
-[15]: #genesis
+[15]: #finality
 
-[16]: #hardforks
+[16]: #genesis
 
-[17]: #bootstrapnodes
+[17]: #hardforks
 
-[18]: #hardfork
+[18]: #bootstrapnodes
 
-[19]: #chainid
+[19]: #hardfork
 
-[20]: #chainname
+[20]: #chainid
 
-[21]: #networkid
+[21]: #chainname
 
-[22]: https://developer.mozilla.org/docs/Web/JavaScript/Reference/Global_Objects/String
+[22]: #networkid
 
-[23]: https://developer.mozilla.org/docs/Web/JavaScript/Reference/Global_Objects/Number
+[23]: https://developer.mozilla.org/docs/Web/JavaScript/Reference/Global_Objects/String
 
-[24]: https://developer.mozilla.org/docs/Web/JavaScript/Reference/Global_Objects/Boolean
+[24]: https://developer.mozilla.org/docs/Web/JavaScript/Reference/Global_Objects/Number
 
 [25]: https://developer.mozilla.org/docs/Web/JavaScript/Reference/Global_Objects/Array
+
+[26]: https://developer.mozilla.org/docs/Web/JavaScript/Reference/Global_Objects/Boolean
diff --git a/index.js b/index.js
index 785c978..4ae9b79 100644
--- a/index.js
+++ b/index.js
@@ -9,11 +9,13 @@ class Common {
    * @constructor
    * @param {String|Number} chain String ('mainnet') or Number (1) chain representation
    * @param {String} hardfork String identifier ('byzantium') for hardfork (optional)
+   * @param {Array} supportedHardforks Limit parameter returns to the given hardforks (optional)
    */
-  constructor (chain, hardfork) {
+  constructor (chain, hardfork, supportedHardforks) {
     this.setChain(chain)
     this._hardfork = null
-    if (hardfork !== undefined) {
+    this._supportedHardforks = supportedHardforks === undefined ? [] : supportedHardforks
+    if (hardfork) {
       this.setHardfork(hardfork)
     }
   }
@@ -45,6 +47,9 @@ class Common {
    * @param {String} hardfork String identifier ('byzantium')
    */
   setHardfork (hardfork) {
+    if (!this._isSupportedHardfork(hardfork)) {
+      throw new Error(`Hardfork ${hardfork} not set as supported in supportedHardforks`)
+    }
     let changed = false
     for (let hfChanges of hardforkChanges) {
       if (hfChanges[0] === hardfork) {
@@ -69,6 +74,8 @@ class Common {
       } else {
         hardfork = this._hardfork
       }
+    } else if (!this._isSupportedHardfork(hardfork)) {
+      throw new Error(`Hardfork ${hardfork} not set as supported in supportedHardforks`)
     }
     return hardfork
   }
@@ -86,6 +93,22 @@ class Common {
     throw new Error(`Hardfork ${hardfork} not defined for chain ${this.chainName()}`)
   }
 
+  /**
+   * Internal helper function to check if a hardfork is set to be supported by the library
+   * @param {String} hardfork Hardfork name
+   * @returns {Boolean} True if hardfork is supported
+   */
+  _isSupportedHardfork (hardfork) {
+    if (this._supportedHardforks.length > 0) {
+      for (let supportedHf of this._supportedHardforks) {
+        if (hardfork === supportedHf) return true
+      }
+    } else {
+      return true
+    }
+    return false
+  }
+
   /**
    * Returns the parameter corresponding to a hardfork
    * @param {String} topic Parameter topic ('gasConfig', 'gasPrices', 'vm', 'pow', 'casper', 'sharding')
@@ -127,9 +150,15 @@ class Common {
    * Checks if a hardfork is active for a given block number
    * @param {String} hardfork Hardfork name
    * @param {Number} blockNumber
+   * @param {Array} opts
+   * @param {Array.Boolean} opts.onlySupported optional, only allow supported HFs (default: false)
    * @returns {Boolean}
    */
-  hardforkIsActiveOnBlock (hardfork, blockNumber) {
+  hardforkIsActiveOnBlock (hardfork, blockNumber, opts) {
+    opts = opts !== undefined ? opts : []
+    if (opts.onlySupported && !this._isSupportedHardfork(hardfork)) {
+      throw new Error(`Not allowed to be called with an unsupported hardfork`)
+    }
     let hfBlock = this.hardforkBlock(hardfork)
     if (hfBlock !== null && blockNumber >= hfBlock) return true
     return false
@@ -138,9 +167,15 @@ class Common {
   /**
    * Checks if the hardfork provided is active on the chain
    * @param {String} hardfork
+   * @param {Array} opts
+   * @param {Array.Boolean} opts.onlySupported optional, only allow supported HFs (default: false)
    * @returns {Boolean}
    */
-  hardforkIsActiveOnChain (hardfork) {
+  hardforkIsActiveOnChain (hardfork, opts) {
+    opts = opts !== undefined ? opts : []
+    if (opts.onlySupported && !this._isSupportedHardfork(hardfork)) {
+      throw new Error(`Not allowed to be called with an unsupported hardfork`)
+    }
     for (let hf of this.hardforks()) {
       if (hf['name'] === hardfork && hf['block'] !== null) return true
     }
@@ -150,14 +185,18 @@ class Common {
   /**
    * Returns the active hardfork switches for the current chain
    * @param {Number} blockNumber up to block if provided, otherwise for the whole chain
+   * @param {Array} opts
+   * @param {Array.Boolean} opts.onlySupported optional, limit results to supported HFs (default: false)
    * @return {Array} Array with hardfork arrays
    */
-  activeHardforks (blockNumber) {
+  activeHardforks (blockNumber, opts) {
+    opts = opts !== undefined ? opts : []
     let activeHardforks = []
     let hfs = this.hardforks()
     for (let hf of hfs) {
       if (hf['block'] === null) continue
-      if (blockNumber !== undefined && blockNumber < hf['block']) break
+      if ((blockNumber !== undefined && blockNumber !== null) && blockNumber < hf['block']) break
+      if (opts.onlySupported && !this._isSupportedHardfork(hf['name'])) continue
 
       activeHardforks.push(hf)
     }
diff --git a/tests/chains.js b/tests/chains.js
index 664cf14..d35ffc6 100644
--- a/tests/chains.js
+++ b/tests/chains.js
@@ -8,6 +8,7 @@ tape('[Common]: Initialization / Chain params', function (t) {
     st.equal(c.chainId(), 1, 'should return correct chain Id')
     st.equal(c.networkId(), 1, 'should return correct network Id')
     st.equal(c.hardfork(), null, 'should set hardfork to null')
+    st.equal(c._isSupportedHardfork('constantinople'), true, 'should not restrict supported HFs')
 
     c = new Common(1)
     st.equal(c.chainName(), 'mainnet', 'should initialize with chain Id')
@@ -22,9 +23,18 @@ tape('[Common]: Initialization / Chain params', function (t) {
     st.end()
   })
 
+  t.test('Should initialize with supportedHardforks provided', function (st) {
+    let c = new Common('mainnet', 'byzantium', ['byzantium', 'constantinople'])
+    st.equal(c._isSupportedHardfork('byzantium'), true, 'should return true for supported HF')
+    st.equal(c._isSupportedHardfork('spuriousDragon'), false, 'should return false for unsupported HF')
+
+    st.end()
+  })
+
   t.test('Should handle initialization errors', function (st) {
     st.throws(function () { new Common('chainnotexisting') }, /not supported$/, 'should throw an exception on non-existing chain') // eslint-disable-line no-new
     st.throws(function () { new Common('mainnet', 'hardforknotexisting') }, /not supported$/, 'should throw an exception on non-existing hardfork') // eslint-disable-line no-new
+    st.throws(function () { new Common('mainnet', 'spuriousDragon', ['byzantium', 'constantinople']) }, /supportedHardforks$/, 'should throw an exception on conflicting active/supported HF params') // eslint-disable-line no-new
 
     st.end()
   })
diff --git a/tests/hardforks.js b/tests/hardforks.js
index bce3df8..f24e521 100644
--- a/tests/hardforks.js
+++ b/tests/hardforks.js
@@ -45,6 +45,9 @@ tape('[Common]: Hardfork logic', function (t) {
     st.equal(c.activeHardforks(9).length, 3, 'should return 3 active hardforks for Ropsten up to block 9')
     st.equal(c.activeHardforks(10).length, 4, 'should return 4 active hardforks for Ropsten up to block 10')
 
+    c = new Common('ropsten', null, ['spuriousDragon', 'byzantium', 'constantinople'])
+    st.equal(c.activeHardforks(null, { onlySupported: true }).length, 2, 'should return 2 active HFs when restricted to supported HFs')
+
     st.end()
   })
 
@@ -54,6 +57,10 @@ tape('[Common]: Hardfork logic', function (t) {
     st.equal(c.hardforkIsActiveOnChain('dao'), false, 'should return false for dao on Ropsten')
     st.equal(c.hardforkIsActiveOnChain('hybridCasper'), false, 'should return false for hybridCasper on Ropsten')
     st.equal(c.hardforkIsActiveOnChain('notexistinghardfork'), false, 'should return false for a non-existing HF on Ropsten')
+    st.doesNotThrow(function () { c.hardforkIsActiveOnChain('spuriousDragon', { onlySupported: true }) }, /unsupported hardfork$/, 'should not throw with unsupported Hf and onlySupported set to false') // eslint-disable-line no-new
+
+    c = new Common('ropsten', null, ['byzantium', 'constantinople'])
+    st.throws(function () { c.hardforkIsActiveOnChain('spuriousDragon', { onlySupported: true }) }, /unsupported hardfork$/, 'should throw with unsupported Hf and onlySupported set to true') // eslint-disable-line no-new
 
     st.end()
   })
diff --git a/tests/params.js b/tests/params.js
index 6655b12..1587776 100644
--- a/tests/params.js
+++ b/tests/params.js
@@ -21,6 +21,10 @@ tape('[Common]: Parameter access', function (t) {
     c.setHardfork('byzantium')
     st.equal(c.param('gasPrices', 'ecAddGas'), 500, 'Should return correct value for HF set in class')
 
+    c = new Common('mainnet', 'byzantium', ['byzantium', 'constantinople'])
+    st.throws(function () { c.param('gasPrices', 'expByte', 'spuriousDragon') }, /supportedHardforks$/, 'Should throw when calling param() with an unsupported hardfork')
+    st.throws(function () { c.paramByBlock('gasPrices', 'expByte', 0) }, /supportedHardforks$/, 'Should throw when calling paramByBlock() with an unsupported hardfork')
+
     st.end()
   })