diff --git a/lodash.js b/lodash.js
index 24f0e6bfd..28681263a 100644
--- a/lodash.js
+++ b/lodash.js
@@ -5171,7 +5171,7 @@
     function isKeyable(value) {
       var type = typeof value;
       return type == 'number' || type == 'boolean' ||
-        (type == 'string' && value !== '__proto__') || value == null;
+        (type == 'string' && value != '__proto__') || value == null;
     }
 
     /**