diff --git a/src/php/lib/Grpc/AbstractCall.php b/src/php/lib/Grpc/AbstractCall.php
index 1d51a8e66caa4af3225534a5482ac002c491e3c4..40387abdc0727c7d793fb66cf5a667f33c663222 100644
--- a/src/php/lib/Grpc/AbstractCall.php
+++ b/src/php/lib/Grpc/AbstractCall.php
@@ -126,7 +126,7 @@ abstract class AbstractCall
      *
      * @return string The protobuf binary format
      */
-    protected function serializeMessage($data)
+    protected function _serializeMessage($data)
     {
         // Proto3 implementation
         if (method_exists($data, 'encode')) {
@@ -144,7 +144,7 @@ abstract class AbstractCall
      *
      * @return mixed The deserialized value
      */
-    protected function deserializeResponse($value)
+    protected function _deserializeResponse($value)
     {
         if ($value === null) {
             return;
diff --git a/src/php/lib/Grpc/BaseStub.php b/src/php/lib/Grpc/BaseStub.php
index a9e77b9396acf948512b0ac487a6901bea12dcac..ed504f85a869a193e48efd9e2726db9fbce2144a 100644
--- a/src/php/lib/Grpc/BaseStub.php
+++ b/src/php/lib/Grpc/BaseStub.php
@@ -145,6 +145,14 @@ class BaseStub
         return $this->_checkConnectivityState($new_state);
     }
 
+    /**
+     * Close the communication channel associated with this stub.
+     */
+    public function close()
+    {
+        $this->channel->close();
+    }
+
     /**
      * @param $new_state Connect state
      *
@@ -163,14 +171,6 @@ class BaseStub
         return false;
     }
 
-    /**
-     * Close the communication channel associated with this stub.
-     */
-    public function close()
-    {
-        $this->channel->close();
-    }
-
     /**
      * constructs the auth uri for the jwt.
      *
@@ -235,7 +235,7 @@ class BaseStub
      *
      * @return SimpleSurfaceActiveCall The active call object
      */
-    public function _simpleRequest($method,
+    protected function _simpleRequest($method,
                                    $argument,
                                    $deserialize,
                                    array $metadata = [],
@@ -270,7 +270,7 @@ class BaseStub
      *
      * @return ClientStreamingSurfaceActiveCall The active call object
      */
-    public function _clientStreamRequest($method,
+    protected function _clientStreamRequest($method,
                                          $deserialize,
                                          array $metadata = [],
                                          array $options = [])
@@ -305,7 +305,7 @@ class BaseStub
      *
      * @return ServerStreamingSurfaceActiveCall The active call object
      */
-    public function _serverStreamRequest($method,
+    protected function _serverStreamRequest($method,
                                          $argument,
                                          $deserialize,
                                          array $metadata = [],
@@ -339,7 +339,7 @@ class BaseStub
      *
      * @return BidiStreamingSurfaceActiveCall The active call object
      */
-    public function _bidiRequest($method,
+    protected function _bidiRequest($method,
                                  $deserialize,
                                  array $metadata = [],
                                  array $options = [])
diff --git a/src/php/lib/Grpc/BidiStreamingCall.php b/src/php/lib/Grpc/BidiStreamingCall.php
index b03bbd204fb447b9efd90efcdf67f7506926093b..7cb200d14100649262a413608101c1a5510583a5 100644
--- a/src/php/lib/Grpc/BidiStreamingCall.php
+++ b/src/php/lib/Grpc/BidiStreamingCall.php
@@ -69,7 +69,7 @@ class BidiStreamingCall extends AbstractCall
             $this->metadata = $read_event->metadata;
         }
 
-        return $this->deserializeResponse($read_event->message);
+        return $this->_deserializeResponse($read_event->message);
     }
 
     /**
@@ -82,7 +82,7 @@ class BidiStreamingCall extends AbstractCall
      */
     public function write($data, array $options = [])
     {
-        $message_array = ['message' => $this->serializeMessage($data)];
+        $message_array = ['message' => $this->_serializeMessage($data)];
         if (array_key_exists('flags', $options)) {
             $message_array['flags'] = $options['flags'];
         }
diff --git a/src/php/lib/Grpc/ClientStreamingCall.php b/src/php/lib/Grpc/ClientStreamingCall.php
index c542f08872744214a3937b0045889df66be26add..6454cbcb218b41bfa461dde13913c716b1f60b58 100644
--- a/src/php/lib/Grpc/ClientStreamingCall.php
+++ b/src/php/lib/Grpc/ClientStreamingCall.php
@@ -63,7 +63,7 @@ class ClientStreamingCall extends AbstractCall
      */
     public function write($data, array $options = [])
     {
-        $message_array = ['message' => $this->serializeMessage($data)];
+        $message_array = ['message' => $this->_serializeMessage($data)];
         if (array_key_exists('flags', $options)) {
             $message_array['flags'] = $options['flags'];
         }
@@ -90,6 +90,6 @@ class ClientStreamingCall extends AbstractCall
         $status = $event->status;
         $this->trailing_metadata = $status->metadata;
 
-        return [$this->deserializeResponse($event->message), $status];
+        return [$this->_deserializeResponse($event->message), $status];
     }
 }
diff --git a/src/php/lib/Grpc/ServerStreamingCall.php b/src/php/lib/Grpc/ServerStreamingCall.php
index 406512bf579497e003eca148b0aaafeccce0c720..8659f6bc2211d5d08c49a58ddd008ba53cf5f66d 100644
--- a/src/php/lib/Grpc/ServerStreamingCall.php
+++ b/src/php/lib/Grpc/ServerStreamingCall.php
@@ -51,7 +51,7 @@ class ServerStreamingCall extends AbstractCall
      */
     public function start($data, array $metadata = [], array $options = [])
     {
-        $message_array = ['message' => $this->serializeMessage($data)];
+        $message_array = ['message' => $this->_serializeMessage($data)];
         if (array_key_exists('flags', $options)) {
             $message_array['flags'] = $options['flags'];
         }
@@ -73,7 +73,7 @@ class ServerStreamingCall extends AbstractCall
             OP_RECV_MESSAGE => true,
         ])->message;
         while ($response !== null) {
-            yield $this->deserializeResponse($response);
+            yield $this->_deserializeResponse($response);
             $response = $this->call->startBatch([
                 OP_RECV_MESSAGE => true,
             ])->message;
diff --git a/src/php/lib/Grpc/UnaryCall.php b/src/php/lib/Grpc/UnaryCall.php
index 3c1cb158ea563df9f8765fac891a955442508f57..b8b1ed6eaea2e30ced061e97f96f2303dd65c919 100644
--- a/src/php/lib/Grpc/UnaryCall.php
+++ b/src/php/lib/Grpc/UnaryCall.php
@@ -51,7 +51,7 @@ class UnaryCall extends AbstractCall
      */
     public function start($data, array $metadata = [], array $options = [])
     {
-        $message_array = ['message' => $this->serializeMessage($data)];
+        $message_array = ['message' => $this->_serializeMessage($data)];
         if (isset($options['flags'])) {
             $message_array['flags'] = $options['flags'];
         }
@@ -79,6 +79,6 @@ class UnaryCall extends AbstractCall
         $status = $event->status;
         $this->trailing_metadata = $status->metadata;
 
-        return [$this->deserializeResponse($event->message), $status];
+        return [$this->_deserializeResponse($event->message), $status];
     }
 }