diff --git a/src/Storage/Connection/Rest.php b/src/Storage/Connection/Rest.php
index 697103fe8c49..da98048e6c7f 100644
--- a/src/Storage/Connection/Rest.php
+++ b/src/Storage/Connection/Rest.php
@@ -43,6 +43,11 @@ class Rest implements ConnectionInterface
     const UPLOAD_URI = 'https://www.googleapis.com/upload/storage/v1/b/{bucket}/o{?query*}';
     const DOWNLOAD_URI = 'https://www.googleapis.com/storage/v1/b/{bucket}/o/{object}{?query*}';
 
+    /**
+     * @var string
+     */
+    private $projectId;
+
     /**
      * @param array $config
      */
@@ -58,6 +63,16 @@ public function __construct(array $config = [])
             $config['serviceDefinitionPath'],
             self::BASE_URI
         ));
+
+        $this->projectId = $this->pluck('projectId', $config, false);
+    }
+
+    /**
+     * @return string
+     */
+    public function projectId()
+    {
+        return $this->projectId;
     }
 
     /**
diff --git a/src/Storage/StorageClient.php b/src/Storage/StorageClient.php
index 764741981377..3ff11624b373 100644
--- a/src/Storage/StorageClient.php
+++ b/src/Storage/StorageClient.php
@@ -92,7 +92,9 @@ public function __construct(array $config = [])
             $config['scopes'] = [self::FULL_CONTROL_SCOPE];
         }
 
-        $this->connection = new Rest($this->configureAuthentication($config));
+        $this->connection = new Rest($this->configureAuthentication($config) + [
+            'projectId' => $this->projectId
+        ]);
     }
 
     /**
diff --git a/tests/unit/Storage/Connection/RestTest.php b/tests/unit/Storage/Connection/RestTest.php
index 16022ad07107..9541e1a69a7b 100644
--- a/tests/unit/Storage/Connection/RestTest.php
+++ b/tests/unit/Storage/Connection/RestTest.php
@@ -104,6 +104,18 @@ public function methodProvider()
         ];
     }
 
+    public function testProjectId()
+    {
+        $rest = new Rest(['projectId' => 'foo']);
+        $this->assertEquals('foo', $rest->projectId());
+    }
+
+    public function testProjectIdNull()
+    {
+        $rest = new Rest();
+        $this->assertNull($rest->projectId());
+    }
+
     public function testDownloadObject()
     {
         $actualRequest = null;