diff --git a/dll/shellext/zipfldr/CZipEnumerator.hpp b/dll/shellext/zipfldr/CZipEnumerator.hpp
index 2c36aac2ea9..9948413d908 100644
--- a/dll/shellext/zipfldr/CZipEnumerator.hpp
+++ b/dll/shellext/zipfldr/CZipEnumerator.hpp
@@ -52,7 +52,8 @@ public:
                     name = tmp.Mid(len, pos - len);
                     folder = true;
                 }
-                tmp = name.MakeLower();
+                tmp = name;
+                tmp.MakeLower();
 
                 POSITION it = m_Returned.Find(tmp);
                 if (!name.IsEmpty() && !it)