diff --git a/src/main/java/com/redislabs/modules/rejson/JReJSON.java b/src/main/java/com/redislabs/modules/rejson/JReJSON.java
index 79c4500..8de79b3 100644
--- a/src/main/java/com/redislabs/modules/rejson/JReJSON.java
+++ b/src/main/java/com/redislabs/modules/rejson/JReJSON.java
@@ -64,12 +64,14 @@ private enum Command implements ProtocolCommand {
         ARRLEN("JSON.ARRLEN"),
         ARRPOP("JSON.ARRPOP"),
         ARRTRIM("JSON.ARRTRIM");
+
         private final byte[] raw;
 
         Command(String alt) {
             raw = SafeEncoder.encode(alt);
         }
 
+        @Override
         public byte[] getRaw() {
             return raw;
         }
@@ -82,12 +84,14 @@ public enum ExistenceModifier implements ProtocolCommand {
         DEFAULT(""),
         NOT_EXISTS("NX"),
         MUST_EXIST("XX");
+
         private final byte[] raw;
 
         ExistenceModifier(String alt) {
             raw = SafeEncoder.encode(alt);
         }
 
+        @Override
         public byte[] getRaw() {
             return raw;
         }
@@ -121,23 +125,14 @@ public JReJSON(Pool<Jedis> jedis) {
         this.client = jedis;
     }
 
-    /**
-     *  Helper to check for errors and throw them as an exception
-     * @param str the reply string to "analyze"
-     * @throws RuntimeException
-     */
-    private static void assertReplyNotError(final String str) {
-        if (str.startsWith("-ERR"))
-            throw new RuntimeException(str.substring(5));
-    }
-
     /**
      * Helper to check for an OK reply
      * @param str the reply string to "scrutinize"
      */
     private static void assertReplyOK(final String str) {
-        if (!str.equals("OK"))
-            throw new RuntimeException(str);
+        if (str == null) {
+            throw new NullPointerException("Null response received.");
+        }
     }
 
     /**
@@ -227,7 +222,7 @@ public <T> T get(String key, Class<T> clazz, Path... paths) {
     		conn.getClient().sendCommand(Command.GET, args);
         	rep = conn.getClient().getBulkReply();
     	}
-    	assertReplyNotError(rep);
+
     	return gson.fromJson(rep, clazz);
     }
 
@@ -356,8 +351,6 @@ public Class<?> type(String key, Path path) {
         	rep = conn.getClient().getBulkReply();
     	}
 
-        assertReplyNotError(rep);
-
         switch (rep) {
             case "null":
                 return null;
@@ -374,7 +367,7 @@ public Class<?> type(String key, Path path) {
             case "array":
                 return List.class;
             default:
-                throw new java.lang.RuntimeException(rep);
+                throw new RuntimeException(rep);
         }
     }
 
@@ -425,7 +418,6 @@ public static Object get(Jedis conn, String key, Path... paths) {
         String rep = conn.getClient().getBulkReply();
         conn.close();
 
-        assertReplyNotError(rep);
         return gson.fromJson(rep, Object.class);
     }
 
@@ -492,8 +484,6 @@ public static Class<?> type(Jedis conn, String key, Path... path) {
         String rep = conn.getClient().getBulkReply();
         conn.close();
 
-        assertReplyNotError(rep);
-
         switch (rep) {
             case "null":
                 return null;
@@ -510,7 +500,7 @@ public static Class<?> type(Jedis conn, String key, Path... path) {
             case "array":
                 return List.class;
             default:
-                throw new java.lang.RuntimeException(rep);
+                throw new RuntimeException(rep);
         }
     }
 
@@ -533,7 +523,7 @@ private Jedis getConnection() {
     public Long strAppend(String key, Path path, Object... objects) {
         List<byte[]> args = new ArrayList<>();
         args.add(SafeEncoder.encode(key));
-        args.add(SafeEncoder.encode(getSingleOptionalPath(path).toString()));
+        args.add(SafeEncoder.encode(path.toString()));
 
         args.addAll(Arrays.stream(objects) //
                 .map(object -> SafeEncoder.encode(gson.toJson(object))) //
@@ -698,7 +688,7 @@ public <T> T arrPop(String key, Class<T> clazz, Path path, Long index) {
             conn.getClient().sendCommand(Command.ARRPOP, args.toArray(new byte[args.size()][]));
             rep = conn.getClient().getBulkReply();
         }
-        assertReplyNotError(rep);
+
         return gson.fromJson(rep, clazz);
     }
 
diff --git a/src/test/java/com/redislabs/modules/rejson/ClientTest.java b/src/test/java/com/redislabs/modules/rejson/ClientTest.java
index daa3575..2493de6 100644
--- a/src/test/java/com/redislabs/modules/rejson/ClientTest.java
+++ b/src/test/java/com/redislabs/modules/rejson/ClientTest.java
@@ -48,6 +48,7 @@
 import com.google.gson.JsonObject;
 
 import redis.clients.jedis.Jedis;
+import redis.clients.jedis.exceptions.JedisDataException;
 
 public class ClientTest {
 
@@ -157,7 +158,7 @@ public void noArgsConstructorReturnsClientToLocalMachine() {
     }
 
     @Test
-    public void basicSetGetShouldSucceed() throws Exception {
+    public void basicSetGetShouldSucceed() {
 
         // naive set with a path
     	client.set("null", null, Path.ROOT_PATH);
@@ -180,7 +181,7 @@ public void basicSetGetShouldSucceed() throws Exception {
     }
 
     @Test
-    public void setExistingPathOnlyIfExistsShouldSucceed() throws Exception {
+    public void setExistingPathOnlyIfExistsShouldSucceed() {
         client.set( "obj", new IRLObject());
         Path p = Path.of(".str");
         client.set( "obj", "strangle", JReJSON.ExistenceModifier.MUST_EXIST, p);
@@ -188,7 +189,7 @@ public void setExistingPathOnlyIfExistsShouldSucceed() throws Exception {
     }
 
     @Test
-    public void setNonExistingOnlyIfNotExistsShouldSucceed() throws Exception {
+    public void setNonExistingOnlyIfNotExistsShouldSucceed() {
         client.set( "obj", new IRLObject());
         Path p = Path.of(".none");
         client.set( "obj", "strangle", JReJSON.ExistenceModifier.NOT_EXISTS, p);
@@ -196,34 +197,34 @@ public void setNonExistingOnlyIfNotExistsShouldSucceed() throws Exception {
     }
 
     @Test
-    public void setWithoutAPathDefaultsToRootPath() throws Exception {
+    public void setWithoutAPathDefaultsToRootPath() {
         client.set( "obj1", new IRLObject());
         client.set( "obj1", "strangle", JReJSON.ExistenceModifier.MUST_EXIST);
         assertEquals("strangle", client.get( "obj1", String.class, Path.ROOT_PATH));
     }
 
-    @Test(expected = Exception.class)
-    public void setExistingPathOnlyIfNotExistsShouldFail() throws Exception {
+    @Test(expected = NullPointerException.class)
+    public void setExistingPathOnlyIfNotExistsShouldFail() {
         client.set( "obj", new IRLObject());
         Path p = Path.of(".str");
         client.set( "obj", "strangle", JReJSON.ExistenceModifier.NOT_EXISTS, p);
     }
 
-    @Test(expected = Exception.class)
-    public void setNonExistingPathOnlyIfExistsShouldFail() throws Exception {
+    @Test(expected = NullPointerException.class)
+    public void setNonExistingPathOnlyIfExistsShouldFail() {
         client.set( "obj", new IRLObject());
         Path p = Path.of(".none");
         client.set( "obj", "strangle", JReJSON.ExistenceModifier.MUST_EXIST, p);
     }
 
-    @Test(expected = Exception.class)
-    public void setException() throws Exception {
+    @Test(expected = JedisDataException.class)
+    public void setException() {
         // should error on non root path for new key
         client.set( "test", "bar", Path.of(".foo"));
     }
 
     @Test
-    public void getMultiplePathsShouldSucceed() throws Exception {
+    public void getMultiplePathsShouldSucceed() {
         // check multiple paths
         IRLObject obj = new IRLObject();
         client.set( "obj", obj);
@@ -232,14 +233,14 @@ public void getMultiplePathsShouldSucceed() throws Exception {
 
     }
 
-    @Test(expected = Exception.class)
-    public void getException() throws Exception {
+    @Test(expected = JedisDataException.class)
+    public void getException() {
         client.set( "test", "foo", Path.ROOT_PATH);
         client.get( "test", String.class, Path.of(".bar"));
     }
 
     @Test
-    public void delValidShouldSucceed() throws Exception {
+    public void delValidShouldSucceed() {
         // check deletion of a single path
         client.set( "obj", new IRLObject(), Path.ROOT_PATH);
         client.del( "obj", Path.of(".str"));
@@ -251,13 +252,13 @@ public void delValidShouldSucceed() throws Exception {
     }
 
     @Test
-    public void delNonExistingPathsAreIgnored() throws Exception {
+    public void delNonExistingPathsAreIgnored() {
 	    client.set( "foobar", new FooBarObject(), Path.ROOT_PATH);
 	    client.del( "foobar", Path.of(".foo[1]")).longValue();
     }
 
     @Test
-    public void typeChecksShouldSucceed() throws Exception {
+    public void typeChecksShouldSucceed() {
         client.set( "foobar", new FooBarObject(), Path.ROOT_PATH);
         assertSame(Object.class, client.type( "foobar"));
         assertSame(Object.class, client.type( "foobar", Path.ROOT_PATH));
@@ -273,20 +274,20 @@ public void typeChecksShouldSucceed() throws Exception {
         }catch(Exception e) {}
     }
 
-    @Test(expected = Exception.class)
-    public void typeException() throws Exception {
+    @Test(expected = NullPointerException.class)
+    public void typeException() {
         client.set( "foobar", new FooBarObject(), Path.ROOT_PATH);
         client.type( "foobar", Path.of(".foo[1]"));
     }
 
-    @Test(expected = Exception.class)
-    public void type1Exception() throws Exception {
+    @Test(expected = NullPointerException.class)
+    public void type1Exception() {
         client.set( "foobar", new FooBarObject(), Path.ROOT_PATH);
         client.type( "foobar", Path.of(".foo[1]"));
     }
 
     @Test
-    public void testMultipleGetAtRootPathAllKeysExist() throws Exception {
+    public void testMultipleGetAtRootPathAllKeysExist() {
         Baz baz1 = new Baz("quuz1", "grault1", "waldo1");
         Baz baz2 = new Baz("quuz2", "grault2", "waldo2");
         Qux qux1 = new Qux("quux1", "corge1", "garply1", baz1);
@@ -317,7 +318,7 @@ public void testMultipleGetAtRootPathAllKeysExist() throws Exception {
     }
 
     @Test
-    public void testMultipleGetAtRootPathWithMissingKeys() throws Exception {
+    public void testMultipleGetAtRootPathWithMissingKeys() {
         Baz baz1 = new Baz("quuz1", "grault1", "waldo1");
         Baz baz2 = new Baz("quuz2", "grault2", "waldo2");
         Qux qux1 = new Qux("quux1", "corge1", "garply1", baz1);
@@ -335,7 +336,7 @@ public void testMultipleGetAtRootPathWithMissingKeys() throws Exception {
     }
 
     @Test
-    public void testMultipleGetWithPathPathAllKeysExist() throws Exception {
+    public void testMultipleGetWithPathPathAllKeysExist() {
         Baz baz1 = new Baz("quuz1", "grault1", "waldo1");
         Baz baz2 = new Baz("quuz2", "grault2", "waldo2");
         Qux qux1 = new Qux("quux1", "corge1", "garply1", baz1);
@@ -362,13 +363,13 @@ public void testMultipleGetWithPathPathAllKeysExist() throws Exception {
     }
 
     @Test
-    public void testArrayLength() throws Exception {
+    public void testArrayLength() {
       client.set( "foobar", new FooBarObject(), Path.ROOT_PATH);
       assertEquals(Long.valueOf(3L), client.arrLen( "foobar", Path.of(".fooArr")));
     }
 
     @Test
-    public void testArrayAppendSameType() throws Exception {
+    public void testArrayAppendSameType() {
       String json = "{ a: 'hello', b: [1, 2, 3], c: { d: ['ello'] }}";
       JsonObject jsonObject = new Gson().fromJson(json, JsonObject.class);    
         
@@ -380,7 +381,7 @@ public void testArrayAppendSameType() throws Exception {
     }
     
     @Test
-    public void testArrayAppendMultipleTypes() throws Exception {
+    public void testArrayAppendMultipleTypes() {
       String json = "{ a: 'hello', b: [1, 2, 3], c: { d: ['ello'] }}";
       JsonObject jsonObject = new Gson().fromJson(json, JsonObject.class);    
         
@@ -395,7 +396,7 @@ public void testArrayAppendMultipleTypes() throws Exception {
     }
     
     @Test
-    public void testArrayAppendMultipleTypesWithDeepPath() throws Exception {
+    public void testArrayAppendMultipleTypesWithDeepPath() {
       String json = "{ a: 'hello', b: [1, 2, 3], c: { d: ['ello'] }}";
       JsonObject jsonObject = new Gson().fromJson(json, JsonObject.class);    
         
@@ -407,7 +408,7 @@ public void testArrayAppendMultipleTypesWithDeepPath() throws Exception {
     }
     
     @Test
-    public void testArrayAppendAgaintsEmptyArray() throws Exception {
+    public void testArrayAppendAgaintsEmptyArray() {
       String json = "{ a: 'hello', b: [1, 2, 3], c: { d: [] }}";
       JsonObject jsonObject = new Gson().fromJson(json, JsonObject.class);  
         
@@ -418,8 +419,8 @@ public void testArrayAppendAgaintsEmptyArray() throws Exception {
       assertArrayEquals(new String[] {"a", "b", "c"}, array);
     }
     
-    @Test(expected = Exception.class)
-    public void testArrayAppendPathIsNotArray() throws Exception {
+    @Test(expected = JedisDataException.class)
+    public void testArrayAppendPathIsNotArray() {
       String json = "{ a: 'hello', b: [1, 2, 3], c: { d: ['ello'] }}";
       JsonObject jsonObject = new Gson().fromJson(json, JsonObject.class);    
         
@@ -428,31 +429,31 @@ public void testArrayAppendPathIsNotArray() throws Exception {
     }
     
     @Test
-    public void testArrayIndexWithInts() throws Exception {
+    public void testArrayIndexWithInts() {
       client.set( "quxquux", new int[] {8,6,7,5,3,0,9}, Path.ROOT_PATH);
       assertEquals(Long.valueOf(2L), client.arrIndex( "quxquux", Path.ROOT_PATH, 7));
     }
 
     @Test
-    public void testArrayIndexWithStrings() throws Exception {
+    public void testArrayIndexWithStrings() {
       client.set( "quxquux", new String[] {"8","6","7","5","3","0","9"}, Path.ROOT_PATH);
       assertEquals(Long.valueOf(2L), client.arrIndex( "quxquux", Path.ROOT_PATH, "7"));
     }
 
     @Test
-    public void testArrayIndexWithStringsAndPath() throws Exception {
+    public void testArrayIndexWithStringsAndPath() {
       client.set( "foobar", new FooBarObject(), Path.ROOT_PATH);
       assertEquals(Long.valueOf(1L), client.arrIndex( "foobar", Path.of(".fooArr"), "b"));
     }
     
-    @Test(expected = Exception.class)
-    public void testArrayIndexNonExistentPath() throws Exception {
+    @Test(expected = JedisDataException.class)
+    public void testArrayIndexNonExistentPath() {
       client.set( "foobar", new FooBarObject(), Path.ROOT_PATH);
       assertEquals(Long.valueOf(1L), client.arrIndex( "foobar", Path.of(".barArr"), "x"));
     }
     
     @Test
-    public void testArrayInsert() throws Exception {
+    public void testArrayInsert() {
       String json = "['hello', 'world', true, 1, 3, null, false]";
       JsonArray jsonArray = new Gson().fromJson(json, JsonArray.class);    
         
@@ -467,7 +468,7 @@ public void testArrayInsert() throws Exception {
     }
     
     @Test
-    public void testArrayInsertWithNegativeIndex() throws Exception {
+    public void testArrayInsertWithNegativeIndex() {
       String json = "['hello', 'world', true, 1, 3, null, false]";
       JsonArray jsonArray = new Gson().fromJson(json, JsonArray.class);    
         
@@ -479,7 +480,7 @@ public void testArrayInsertWithNegativeIndex() throws Exception {
     }
     
     @Test
-    public void testArrayPop() throws Exception {
+    public void testArrayPop() {
       client.set( "arr", new int[] {0,1,2,3,4}, Path.ROOT_PATH);
       assertEquals(Long.valueOf(4L), client.arrPop( "arr", Long.class, Path.ROOT_PATH, 4L));
       assertEquals(Long.valueOf(3L), client.arrPop( "arr", Long.class, Path.ROOT_PATH, -1L));
@@ -489,7 +490,7 @@ public void testArrayPop() throws Exception {
     }
     
     @Test
-    public void testArrayTrim() throws Exception {
+    public void testArrayTrim() {
       client.set( "arr", new int[] {0,1,2,3,4}, Path.ROOT_PATH);
       assertEquals(Long.valueOf(3L), client.arrTrim( "arr", Path.ROOT_PATH, 1L, 3L));
       
@@ -498,14 +499,14 @@ public void testArrayTrim() throws Exception {
     }
     
     @Test
-    public void testStringAppend() throws Exception {
+    public void testStringAppend() {
       client.set( "str", "foo", Path.ROOT_PATH);
       assertEquals(Long.valueOf(6L), client.strAppend( "str", Path.ROOT_PATH, "bar"));
       assertEquals("foobar", client.get("str", String.class, Path.ROOT_PATH));
     }
     
     @Test
-    public void testStringLen() throws Exception {
+    public void testStringLen() {
       client.set( "str", "foo", Path.ROOT_PATH);
       assertEquals(Long.valueOf(3L), client.strLen( "str", Path.ROOT_PATH));
     }