diff --git a/test/unit/instrumentation/mysql/wrapCreatePoolCluster.test.js b/test/unit/instrumentation/mysql/wrapCreatePoolCluster.test.js
index 8227aa98b2..bdc3a65a7c 100644
--- a/test/unit/instrumentation/mysql/wrapCreatePoolCluster.test.js
+++ b/test/unit/instrumentation/mysql/wrapCreatePoolCluster.test.js
@@ -38,7 +38,7 @@ tap.test('wrapCreatePoolCluster', (t) => {
     }
 
     mockPoolCluster = {
-      of: sinon.stub.returns(),
+      of: sinon.stub().returns(),
       getConnection: sinon.stub().returns()
     }