diff --git a/src/test/__tests__/ReactDefaultPerf-test.js b/src/test/__tests__/ReactDefaultPerf-test.js
index 42c32518e4..716cbdf06b 100644
--- a/src/test/__tests__/ReactDefaultPerf-test.js
+++ b/src/test/__tests__/ReactDefaultPerf-test.js
@@ -58,7 +58,7 @@ describe('ReactDefaultPerf', function() {
     ReactDefaultPerf.start();
     fn();
     ReactDefaultPerf.stop();
-    return ReactDefaultPerf.getLastMeasurements();
+    return ReactDefaultPerf.getLastMeasurements().__unstable_this_format_will_change;
   }
 
   it('should count no-op update as waste', function() {