diff --git a/mozilla/extensions/transformiix/source/base/txExpandedNameMap.cpp b/mozilla/extensions/transformiix/source/base/txExpandedNameMap.cpp
index f148de3935e..31ca35807f0 100644
--- a/mozilla/extensions/transformiix/source/base/txExpandedNameMap.cpp
+++ b/mozilla/extensions/transformiix/source/base/txExpandedNameMap.cpp
@@ -176,7 +176,7 @@ TxObject* txExpandedNameMap::remove(const txExpandedName& aKey)
             }
             --mItemCount;
             if (i != mItemCount) {
-                memmove(&mItems[i], &mItems[mItemCount], sizeof(MapItem));
+                memcpy(&mItems[i], &mItems[mItemCount], sizeof(MapItem));
             }
         }
     }