diff --git a/lodash.js b/lodash.js
index 5e43d2191..a1be79e01 100644
--- a/lodash.js
+++ b/lodash.js
@@ -1520,7 +1520,7 @@
 
     while (length--) {
       if (stackA[length] == a) {
-        return stackA[length] == b;
+        return stackB[length] == b;
       }
     }