diff --git a/Spanner/src/Connection/Grpc.php b/Spanner/src/Connection/Grpc.php
index a39f74bee306..61bba6fef413 100644
--- a/Spanner/src/Connection/Grpc.php
+++ b/Spanner/src/Connection/Grpc.php
@@ -137,6 +137,7 @@ private function enableConnectionManagement($conf_path)
      */
     public function __construct(array $config = [])
     {
+	putenv('ENABLE_GCP_OPTIMIZER=TRUE');
         $this->serializer = new Serializer([
             'commit_timestamp' => function ($v) {
                 return $this->formatTimestampFromApi($v);
@@ -165,7 +166,7 @@ public function __construct(array $config = [])
                 : null
         );
 
-        if (isset($config['enableGcpOptimizer'])) {
+        if (getenv('ENABLE_GCP_OPTIMIZER')) {
             $api = 'spanner';
             $conf_path = __DIR__. "/../$api.grpc.config";
             $grpc_gcp_config = $this->enableConnectionManagement($conf_path);