diff --git a/src/isomorphic/classic/types/ReactPropTypes.js b/src/isomorphic/classic/types/ReactPropTypes.js
index 5e8b1d23913d..ef06d4a1826a 100644
--- a/src/isomorphic/classic/types/ReactPropTypes.js
+++ b/src/isomorphic/classic/types/ReactPropTypes.js
@@ -411,7 +411,7 @@ function getPreciseType(propValue) {
 // Returns class name of the object, if any.
 function getClassName(propValue) {
   if (!propValue.constructor || !propValue.constructor.name) {
-    return '<<anonymous>>';
+    return ANONYMOUS;
   }
   return propValue.constructor.name;
 }