diff --git a/composer.json b/composer.json
index 875ec55d8a0dab7b33423991619d1518699a8254..1d78a2ce210bc270c7fccdd28a2f17167a1c14bb 100644
--- a/composer.json
+++ b/composer.json
@@ -2,6 +2,7 @@
   "name": "grpc/grpc",
   "type": "library",
   "description": "gRPC library for PHP",
+  "version": "0.5.1",
   "keywords": ["rpc"],
   "homepage": "http://grpc.io",
   "license": "BSD-3-Clause",
diff --git a/src/php/composer.json b/src/php/composer.json
index b0115bdadd240a8058dd457df888c31823bdcafa..2d0fe0c87a296fb6e6edc0059a95995dd22d8d97 100644
--- a/src/php/composer.json
+++ b/src/php/composer.json
@@ -1,7 +1,7 @@
 {
   "name": "grpc/grpc",
   "description": "gRPC library for PHP",
-  "version": "0.5.0",
+  "version": "0.5.1",
   "homepage": "http://grpc.io",
   "license": "BSD-3-Clause",
   "repositories": [
diff --git a/src/php/lib/Grpc/BaseStub.php b/src/php/lib/Grpc/BaseStub.php
index 48c00977eb8ec9290ef0928132b9beca522e6c81..8c438e4bf92e6ac9a858a62f8de6d5c1e7b37d4d 100755
--- a/src/php/lib/Grpc/BaseStub.php
+++ b/src/php/lib/Grpc/BaseStub.php
@@ -60,7 +60,10 @@ class BaseStub {
       }
       unset($opts['update_metadata']);
     }
-         
+    $package_config = json_decode(
+        file_get_contents(dirname(__FILE__) . '/../../composer.json'), true);
+    $opts['grpc.primary_user_agent'] =
+        'grpc-php/' . $package_config['version'];
     $this->channel = new Channel($hostname, $opts);
   }