diff --git a/src/php/tests/generated_code/AbstractGeneratedCodeTest.php b/src/php/tests/generated_code/AbstractGeneratedCodeTest.php
index 1fe81b9d5491500b5bf602968f8873b0891f0627..75922d4cf7c7fd16eb736cd91fb0a4236f9aee36 100644
--- a/src/php/tests/generated_code/AbstractGeneratedCodeTest.php
+++ b/src/php/tests/generated_code/AbstractGeneratedCodeTest.php
@@ -106,6 +106,34 @@ abstract class AbstractGeneratedCodeTest extends PHPUnit_Framework_TestCase
         $this->assertSame(\Grpc\STATUS_CANCELLED, $status->code);
     }
 
+    public function testCallCredentialsCallback()
+    {
+        $div_arg = new math\DivArgs();
+        $call = self::$client->Div($div_arg, array(), array(
+            'call_credentials_callback' => function ($context) {
+                return array();
+            },
+        ));
+        $call->cancel();
+        list($response, $status) = $call->wait();
+        $this->assertSame(\Grpc\STATUS_CANCELLED, $status->code);
+    }
+
+    public function testCallCredentialsCallback2()
+    {
+        $div_arg = new math\DivArgs();
+        $call = self::$client->Div($div_arg);
+        $call_credentials = Grpc\CallCredentials::createFromPlugin(
+            function ($context) {
+                return array();
+            }
+        );
+        $call->setCallCredentials($call_credentials);
+        $call->cancel();
+        list($response, $status) = $call->wait();
+        $this->assertSame(\Grpc\STATUS_CANCELLED, $status->code);
+    }
+
     /**
      * @expectedException InvalidArgumentException
      */
@@ -118,6 +146,23 @@ abstract class AbstractGeneratedCodeTest extends PHPUnit_Framework_TestCase
         $invalid_client->InvalidUnaryCall($div_arg);
     }
 
+    /**
+     * @expectedException Exception
+     */
+    public function testMissingCredentials()
+    {
+        $invalid_client = new DummyInvalidClient('host', [
+        ]);
+    }
+
+    public function testPrimaryUserAgentString()
+    {
+        $invalid_client = new DummyInvalidClient('host', [
+            'credentials' => Grpc\ChannelCredentials::createInsecure(),
+            'grpc.primary_user_agent' => 'testUserAgent',
+        ]);
+    }
+
     public function testWriteFlags()
     {
         $div_arg = new math\DivArgs();
diff --git a/src/php/tests/unit_tests/CallCredentials2Test.php b/src/php/tests/unit_tests/CallCredentials2Test.php
new file mode 100644
index 0000000000000000000000000000000000000000..a57e2b9b4ee568533b6ed9b89ab2524ba78a5b9b
--- /dev/null
+++ b/src/php/tests/unit_tests/CallCredentials2Test.php
@@ -0,0 +1,135 @@
+<?php
+/*
+ *
+ * Copyright 2015, Google Inc.
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are
+ * met:
+ *
+ *     * Redistributions of source code must retain the above copyright
+ * notice, this list of conditions and the following disclaimer.
+ *     * Redistributions in binary form must reproduce the above
+ * copyright notice, this list of conditions and the following disclaimer
+ * in the documentation and/or other materials provided with the
+ * distribution.
+ *     * Neither the name of Google Inc. nor the names of its
+ * contributors may be used to endorse or promote products derived from
+ * this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+ * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+ * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+ * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ *
+ */
+
+class CallCredentials2Test extends PHPUnit_Framework_TestCase
+{
+    public function setUp()
+    {
+        $credentials = Grpc\ChannelCredentials::createSsl(
+            file_get_contents(dirname(__FILE__).'/../data/ca.pem'));
+        $server_credentials = Grpc\ServerCredentials::createSsl(
+            null,
+            file_get_contents(dirname(__FILE__).'/../data/server1.key'),
+            file_get_contents(dirname(__FILE__).'/../data/server1.pem'));
+        $this->server = new Grpc\Server();
+        $this->port = $this->server->addSecureHttp2Port('0.0.0.0:0',
+                                              $server_credentials);
+        $this->server->start();
+        $this->host_override = 'foo.test.google.fr';
+        $this->channel = new Grpc\Channel(
+            'localhost:'.$this->port,
+            [
+            'grpc.ssl_target_name_override' => $this->host_override,
+            'grpc.default_authority' => $this->host_override,
+            'credentials' => $credentials,
+            ]
+        );
+    }
+
+    public function tearDown()
+    {
+        unset($this->channel);
+        unset($this->server);
+    }
+
+    public function callbackFunc($context)
+    {
+        $this->assertTrue(is_string($context->service_url));
+        $this->assertTrue(is_string($context->method_name));
+
+        return ['k1' => ['v1'], 'k2' => ['v2']];
+    }
+
+    public function testCreateFromPlugin()
+    {
+        $deadline = Grpc\Timeval::infFuture();
+        $status_text = 'xyz';
+        $call = new Grpc\Call($this->channel,
+                              '/abc/dummy_method',
+                              $deadline,
+                              $this->host_override);
+
+        $call_credentials = Grpc\CallCredentials::createFromPlugin(
+            array($this, 'callbackFunc'));
+        $call->setCredentials($call_credentials);
+
+        $event = $call->startBatch([
+            Grpc\OP_SEND_INITIAL_METADATA => [],
+            Grpc\OP_SEND_CLOSE_FROM_CLIENT => true,
+        ]);
+
+        $this->assertTrue($event->send_metadata);
+        $this->assertTrue($event->send_close);
+
+        $event = $this->server->requestCall();
+
+        $this->assertTrue(is_array($event->metadata));
+        $metadata = $event->metadata;
+        $this->assertTrue(array_key_exists('k1', $metadata));
+        $this->assertTrue(array_key_exists('k2', $metadata));
+        $this->assertSame($metadata['k1'], ['v1']);
+        $this->assertSame($metadata['k2'], ['v2']);
+
+        $this->assertSame('/abc/dummy_method', $event->method);
+        $server_call = $event->call;
+
+        $event = $server_call->startBatch([
+            Grpc\OP_SEND_INITIAL_METADATA => [],
+            Grpc\OP_SEND_STATUS_FROM_SERVER => [
+                'metadata' => [],
+                'code' => Grpc\STATUS_OK,
+                'details' => $status_text,
+            ],
+            Grpc\OP_RECV_CLOSE_ON_SERVER => true,
+        ]);
+
+        $this->assertTrue($event->send_metadata);
+        $this->assertTrue($event->send_status);
+        $this->assertFalse($event->cancelled);
+
+        $event = $call->startBatch([
+            Grpc\OP_RECV_INITIAL_METADATA => true,
+            Grpc\OP_RECV_STATUS_ON_CLIENT => true,
+        ]);
+
+        $this->assertSame([], $event->metadata);
+        $status = $event->status;
+        $this->assertSame([], $status->metadata);
+        $this->assertSame(Grpc\STATUS_OK, $status->code);
+        $this->assertSame($status_text, $status->details);
+
+        unset($call);
+        unset($server_call);
+    }
+}