diff --git a/lib/util.js b/lib/util.js
index 6128c36a98..2417392a2d 100644
--- a/lib/util.js
+++ b/lib/util.js
@@ -231,10 +231,10 @@ function ensureDebugIsInitialized() {
 
 
 function inspectPromise(p) {
-  ensureDebugIsInitialized();
   // Only create a mirror if the object is a Promise.
   if (!binding.isPromise(p))
     return null;
+  ensureDebugIsInitialized();
   const mirror = Debug.MakeMirror(p, true);
   return {status: mirror.status(), value: mirror.promiseValue().value_};
 }