diff --git a/lib/client.js b/lib/client.js
index 3166a6c..afa8ed0 100644
--- a/lib/client.js
+++ b/lib/client.js
@@ -29,6 +29,11 @@ Client.prototype.setSocket = function(socket) {
     while (true) {
       parsed = parsePacket(incomingBuffer, self.isServer);
       if (! parsed) break;
+      if (parsed.error) {
+          this.emit('error', parsed.error);
+          this.end("ProtocolError");
+          return;
+      }
       packet = parsed.results;
       incomingBuffer = incomingBuffer.slice(parsed.size);
       self.emit(packet.id, packet);
diff --git a/lib/protocol.js b/lib/protocol.js
index 6d3148c..2c5598c 100644
--- a/lib/protocol.js
+++ b/lib/protocol.js
@@ -727,9 +727,17 @@ function readEntityMetadata(buffer, offset) {
     type = item >> 5;
     typeName = entityMetadataTypes[type];
     dataType = types[typeName];
-    assert.ok(dataType, "unrecognized entity metadata type " + type);
+    if (!dataType) {
+      return {
+        error: new Error("unrecognized entity metadata type " + type)
+      }
+    }
     reader = dataType[0];
-    assert.ok(reader, "missing reader for entity metadata type " + type);
+    if (!reader) {
+      return {
+        error: new Error("missing reader for entity metadata type " + type)
+      }
+    }
     results = reader(buffer, cursor);
     if (! results) return null;
     metadata.push({
@@ -808,7 +816,11 @@ function readMapChunkBulk (buffer, offset) {
     });
   }
 
-  assert.strictEqual(chunkColumnCount, meta.length);
+  if (chunkColumnCount !== meta.length) {
+    return {
+      error: new Error("ChunkColumnCount different from length of meta")
+    }
+  }
 
   return {
     value: {
@@ -1163,7 +1175,9 @@ LongWriter.prototype.write = function(buffer, offset) {
 
 function get(packetId, toServer) {
   var packetInfo = packets[packetId];
-  assert.ok(packetInfo, "unrecognized packet id: " + packetId);
+  if (!packetInfo) {
+    return null;
+  }
   return Array.isArray(packetInfo) ?
     packetInfo :
     toServer ?
@@ -1175,6 +1189,7 @@ function createPacketBuffer(packetId, params, isServer) {
   var size = 1;
   var fields = [ new UByteWriter(packetId) ];
   var packet = get(packetId, !isServer);
+  assert.notEqual(packet, null);
   packet.forEach(function(fieldInfo) {
     var value = params[fieldInfo.name];
     var Writer = types[fieldInfo.type][1];
@@ -1198,14 +1213,28 @@ function parsePacket(buffer, isServer) {
   var size = 1;
   var results = { id: packetId };
   var packetInfo = get(packetId, isServer);
-  assert.ok(packetInfo, "Unrecognized packetId: " + packetId);
+  if (packetInfo == null) {
+    return {
+      error: new Error("Unrecognized packetId: " + packetId)
+    }
+  }
   var i, fieldInfo, read, readResults;
   for (i = 0; i < packetInfo.length; ++i) {
     fieldInfo = packetInfo[i];
     read = types[fieldInfo.type][0];
-    assert.ok(read, "missing reader for data type: " + fieldInfo.type);
+    if (!read) {
+      return {
+        error: new Error("missing reader for data type: " + fieldInfo.type)
+      }
+    }
     readResults = read(buffer, size);
     if (readResults) {
+      // if readResults.error is undef, error stays undef'd
+      if (readResults.error) {
+        return {
+          error: readResults.error
+        }
+      }
       results[fieldInfo.name] = readResults.value;
       size += readResults.size;
     } else {