diff --git a/packages/datastore/src/index.js b/packages/datastore/src/index.js
index 9c56b261f14a..22f1c84687b6 100644
--- a/packages/datastore/src/index.js
+++ b/packages/datastore/src/index.js
@@ -325,7 +325,10 @@ function Datastore(options) {
     service: 'datastore',
     apiVersion: 'v1',
     scopes: ['https://www.googleapis.com/auth/datastore'],
-    userAgent: PKG.name + '/' + PKG.version
+    userAgent: PKG.name + '/' + PKG.version,
+    grpcMetadata: {
+      'google-cloud-resource-prefix': 'projects/' + this.projectId
+    }
   };
 
   common.GrpcService.call(this, config, options);
diff --git a/packages/datastore/test/index.js b/packages/datastore/test/index.js
index 567b9e5a9400..64e3e1544bb0 100644
--- a/packages/datastore/test/index.js
+++ b/packages/datastore/test/index.js
@@ -158,6 +158,9 @@ describe('Datastore', function() {
         'https://www.googleapis.com/auth/datastore'
       ]);
       assert.strictEqual(calledWith.userAgent, PKG.name + '/' + PKG.version);
+      assert.deepEqual(calledWith.grpcMetadata, {
+        'google-cloud-resource-prefix': 'projects/' + datastore.projectId
+      });
     });
   });