diff --git a/src/node/interop/interop_client.js b/src/node/interop/interop_client.js
index a59a66b2aa9dc173a6b7ef7fc303e75ba7dd91f3..46ddecfb1f630711bffac1eac0240488784d6f57 100644
--- a/src/node/interop/interop_client.js
+++ b/src/node/interop/interop_client.js
@@ -380,7 +380,6 @@ function unimplementedService(client, done) {
   client.unimplementedCall({}, function(err, resp) {
     assert(err);
     assert.strictEqual(err.code, grpc.status.UNIMPLEMENTED);
-    assert(!err.message);
     done();
   });
 }