diff --git a/ext/call.cc b/ext/call.cc
index 7e79a612..b08a9f96 100644
--- a/ext/call.cc
+++ b/ext/call.cc
@@ -184,6 +184,9 @@ Local<Value> Op::GetOpType() const {
   return scope.Escape(Nan::New(GetTypeString()).ToLocalChecked());
 }
 
+Op::~Op() {
+}
+
 class SendMetadataOp : public Op {
  public:
   Local<Value> GetNodeValue() const {
@@ -359,7 +362,7 @@ class ReadMessageOp : public Op {
   }
   ~ReadMessageOp() {
     if (recv_message != NULL) {
-      gpr_free(recv_message);
+      grpc_byte_buffer_destroy(recv_message);
     }
   }
   Local<Value> GetNodeValue() const {
diff --git a/ext/call.h b/ext/call.h
index 1f387edc..2f8e1f17 100644
--- a/ext/call.h
+++ b/ext/call.h
@@ -78,6 +78,7 @@ class Op {
   virtual v8::Local<v8::Value> GetNodeValue() const = 0;
   virtual bool ParseOp(v8::Local<v8::Value> value, grpc_op *out,
                        shared_ptr<Resources> resources) = 0;
+  virtual ~Op();
   v8::Local<v8::Value> GetOpType() const;
 
  protected:
@@ -85,7 +86,6 @@ class Op {
 };
 
 typedef std::vector<unique_ptr<Op>> OpVec;
-
 struct tag {
   tag(Nan::Callback *callback, OpVec *ops,
       shared_ptr<Resources> resources);
diff --git a/src/server.js b/src/server.js
index b6f162ad..70b4a9d8 100644
--- a/src/server.js
+++ b/src/server.js
@@ -276,6 +276,7 @@ function ServerWritableStream(call, serialize) {
 function _write(chunk, encoding, callback) {
   /* jshint validthis: true */
   var batch = {};
+  var self = this;
   if (!this.call.metadataSent) {
     batch[grpc.opType.SEND_INITIAL_METADATA] =
         (new Metadata())._getCoreRepresentation();
@@ -290,7 +291,7 @@ function _write(chunk, encoding, callback) {
   batch[grpc.opType.SEND_MESSAGE] = message;
   this.call.startBatch(batch, function(err, value) {
     if (err) {
-      this.emit('error', err);
+      self.emit('error', err);
       return;
     }
     callback();
@@ -305,6 +306,7 @@ ServerWritableStream.prototype._write = _write;
  */
 function sendMetadata(responseMetadata) {
   /* jshint validthis: true */
+  var self = this;
   if (!this.call.metadataSent) {
     this.call.metadataSent = true;
     var batch = [];
@@ -312,7 +314,7 @@ function sendMetadata(responseMetadata) {
         responseMetadata._getCoreRepresentation();
     this.call.startBatch(batch, function(err) {
       if (err) {
-        this.emit('error', err);
+        self.emit('error', err);
         return;
       }
     });