diff --git a/lib/common/grpc-service.js b/lib/common/grpc-service.js
index 9c9de954361..f26b845c75c 100644
--- a/lib/common/grpc-service.js
+++ b/lib/common/grpc-service.js
@@ -20,7 +20,6 @@
 
 'use strict';
 
-var extend = require('extend');
 var googleProtoFiles = require('google-proto-files');
 var grpc = require('grpc');
 var is = require('is');
@@ -456,9 +455,13 @@ GrpcService.createDeadline_ = function(timeout) {
  * @return {error|null}
  */
 GrpcService.getError_ = function(err) {
-  if (GRPC_ERROR_CODE_TO_HTTP[err.code]) {
-    return extend(true, {}, err, GRPC_ERROR_CODE_TO_HTTP[err.code]);
+  if (err && GRPC_ERROR_CODE_TO_HTTP[err.code]) {
+    var defaultErrorDetails = GRPC_ERROR_CODE_TO_HTTP[err.code];
+    err.code = defaultErrorDetails.code;
+    err.message = err.message || defaultErrorDetails.message;
+    return err;
   }
+
   return null;
 };
 
diff --git a/test/common/grpc-service.js b/test/common/grpc-service.js
index 6f30a3563a0..e2230db9559 100644
--- a/test/common/grpc-service.js
+++ b/test/common/grpc-service.js
@@ -1133,7 +1133,19 @@ describe('GrpcService', function() {
       });
     });
 
-    it('should return null for unknown errors', function() {
+    it('should use the message from the error', function() {
+      var errorMessage = 'This is an error message.';
+
+      var err = {
+        code: 1,
+        message: errorMessage
+      };
+
+      var error = GrpcService.getError_(err);
+      assert.strictEqual(error.message, errorMessage);
+    });
+
+    it('should return the original object for unknown errors', function() {
       var error = GrpcService.getError_({ code: 9999 });
 
       assert.strictEqual(error, null);