diff --git a/test.js b/test.js
index 0692553..ae774f4 100644
--- a/test.js
+++ b/test.js
@@ -99,6 +99,21 @@ function testParseGenerateDefaults(name, object, buffer, opts) {
   })
 }
 
+function testWriteToStreamError(expected, fixture) {
+  test('writeToStream ' + expected + ' error', function(t) {
+    t.plan(2)
+
+    var stream = WS()
+
+    stream.write = () => t.fail('should not have called write')
+    stream.on('error', () => t.pass('error emitted'))
+
+    var result = mqtt.writeToStream(fixture, stream)
+
+    t.false(result, 'result should be false')
+  })
+}
+
 testParseGenerate('minimal connect', {
     cmd: 'connect'
   , retain: false
@@ -1026,3 +1041,18 @@ test('stops parsing after first error', function(t) {
     224, 0, // Header
   ]))
 })
+
+testWriteToStreamError('Invalid protocol id', {
+  cmd: 'connect',
+  protocolId: {}
+})
+
+testWriteToStreamError('Invalid topic', {
+  cmd: 'publish',
+  topic: {}
+})
+
+testWriteToStreamError('Invalid message id', {
+  cmd: 'subscribe',
+  mid: {}
+})
diff --git a/writeToStream.js b/writeToStream.js
index ede9db8..b811f09 100644
--- a/writeToStream.js
+++ b/writeToStream.js
@@ -67,6 +67,7 @@ function connect(opts, stream) {
   if (!protocolId ||
      (typeof protocolId !== "string" && !Buffer.isBuffer(protocolId))) {
     stream.emit('error', new Error('Invalid protocol id'))
+    return false
   } else {
     length += protocolId.length + 2
   }
@@ -74,6 +75,7 @@ function connect(opts, stream) {
   // Must be 3 or 4
   if (protocolVersion !== 3 && protocolVersion !== 4) {
     stream.emit('error', new Error('Invalid protocol version'))
+    return false
   } else {
     length += 1
   }
@@ -87,11 +89,13 @@ function connect(opts, stream) {
   } else {
 
     if (protocolVersion < 4) {
-      stream.emit('error', new Error('clientId must be supplied before 3.1.1'));
+      stream.emit('error', new Error('clientId must be supplied before 3.1.1'))
+      return false
     }
 
     if (clean == 0) {
-      stream.emit('error', new Error('clientId must be given if cleanSession set to 0'));
+      stream.emit('error', new Error('clientId must be given if cleanSession set to 0'))
+      return false
     }
   }
 
@@ -101,6 +105,7 @@ function connect(opts, stream) {
       keepalive > 65535 ||
       keepalive % 1 !== 0) {
     stream.emit('error', new Error('Invalid keepalive'))
+    return false
   } else {
     length += 2
   }
@@ -113,10 +118,12 @@ function connect(opts, stream) {
     // It must be an object
     if ('object' !== typeof will) {
       stream.emit('error', new Error('Invalid will'))
+      return false
     }
     // It must have topic typeof string
     if (!will.topic || 'string' !== typeof will.topic) {
       stream.emit('error', new Error('Invalid will topic'))
+      return false
     } else {
       length += Buffer.byteLength(will.topic) + 2
     }
@@ -131,6 +138,7 @@ function connect(opts, stream) {
         }
       } else {
         stream.emit('error', new Error('Invalid will payload'))
+        return false
       }
     } else {
       length += 2
@@ -143,6 +151,7 @@ function connect(opts, stream) {
       length += Buffer.byteLength(username) + 2
     } else {
       stream.emit('error', new Error('Invalid username'))
+      return false
     }
   }
 
@@ -152,6 +161,7 @@ function connect(opts, stream) {
       length += byteLength(password) + 2
     } else {
       stream.emit('error', new Error('Invalid password'))
+      return false
     }
   }
 
@@ -211,8 +221,10 @@ function connack(opts, stream) {
     , rc = opts.returnCode;
 
   // Check return code
-  if ('number' !== typeof rc)
-    stream.emit('error', new Error('Invalid return code'));
+  if ('number' !== typeof rc) {
+    stream.emit('error', new Error('Invalid return code'))
+    return false
+  }
 
   stream.write(protocol.CONNACK_HEADER);
   writeLength(stream, 2);
@@ -237,8 +249,10 @@ function publish(opts, stream) {
     length += Buffer.byteLength(topic) + 2;
   else if (Buffer.isBuffer(topic))
     length += topic.length + 2;
-  else
+  else {
     stream.emit('error', new Error('Invalid topic'));
+    return false;
+  }
 
   // get the payload length
   if (!Buffer.isBuffer(payload)) {
@@ -250,6 +264,7 @@ function publish(opts, stream) {
   // Message id must a number if qos > 0
   if (qos && 'number' !== typeof id) {
     stream.emit('error', new Error('Invalid message id'))
+    return false
   } else if (qos) {
     length += 2;
   }
@@ -285,8 +300,10 @@ function confirmation(opts, stream) {
     qos = 1
 
   // Check message ID
-  if ('number' !== typeof id)
+  if ('number' !== typeof id) {
     stream.emit('error', new Error('Invalid message id'));
+    return false
+  }
 
   // Header
   stream.write(protocol.ACKS[type][qos][dup][0])
@@ -310,6 +327,7 @@ function subscribe(opts, stream) {
   // Check mid
   if ('number' !== typeof id) {
     stream.emit('error', new Error('Invalid message id'));
+    return false
   } else {
     length += 2;
   }
@@ -321,15 +339,18 @@ function subscribe(opts, stream) {
 
       if ('string' !== typeof topic) {
         stream.emit('error', new Error('Invalid subscriptions - invalid topic'));
+        return false
       }
       if ('number' !== typeof qos) {
         stream.emit('error', new Error('Invalid subscriptions - invalid qos'));
+        return false;
       }
 
       length += Buffer.byteLength(topic) + 2 + 1;
     }
   } else {
     stream.emit('error', new Error('Invalid subscriptions'));
+    return false;
   }
 
   // Generate header
@@ -368,6 +389,7 @@ function suback(opts, stream) {
   // Check message id
   if ('number' !== typeof id) {
     stream.emit('error', new Error('Invalid message id'));
+    return false;
   } else {
     length += 2;
   }
@@ -376,11 +398,13 @@ function suback(opts, stream) {
     for (var i = 0; i < granted.length; i += 1) {
       if ('number' !== typeof granted[i]) {
         stream.emit('error', new Error('Invalid qos vector'));
+        return false;
       }
       length += 1;
     }
   } else {
     stream.emit('error', new Error('Invalid qos vector'));
+    return false;
   }
 
   // header
@@ -406,6 +430,7 @@ function unsubscribe(opts, stream) {
   // Check message id
   if ('number' !== typeof id) {
     stream.emit('error', new Error('Invalid message id'));
+    return false;
   } else {
     length += 2;
   }
@@ -414,11 +439,13 @@ function unsubscribe(opts, stream) {
     for (var i = 0; i < unsubs.length; i += 1) {
       if ('string' !== typeof unsubs[i]) {
         stream.emit('error', new Error('Invalid unsubscriptions'));
+        return false;
       }
       length += Buffer.byteLength(unsubs[i]) + 2;
     }
   } else {
     stream.emit('error', new Error('Invalid unsubscriptions'));
+    return false;
   }
 
   // Header