diff --git a/lodash.js b/lodash.js
index 3fef2c8e8..57ac04642 100644
--- a/lodash.js
+++ b/lodash.js
@@ -5794,7 +5794,7 @@
      * @param {*} value The value to check.
      * @returns {boolean} Returns `true` if `func` is maskable, else `false`.
      */
-    var isMaskable = !coreJsData ? stubFalse : isFunction;
+    var isMaskable = coreJsData ? isFunction : stubFalse;
 
     /**
      * Checks if `value` is likely a prototype object.