diff --git a/lodash.js b/lodash.js
index 5f7a6d649..90883f2e5 100644
--- a/lodash.js
+++ b/lodash.js
@@ -6115,7 +6115,6 @@
         // Recursively merge objects and arrays (susceptible to call stack limits).
         stack.set(srcValue, objValue);
         baseMerge(objValue, srcValue, undefined, mergeDefaults, stack);
-        stack['delete'](srcValue);
       }
       return objValue;
     }