diff --git a/dlls/shell32/shfldr_fs.c b/dlls/shell32/shfldr_fs.c
index 830013bba09..94080d0b6e1 100644
--- a/dlls/shell32/shfldr_fs.c
+++ b/dlls/shell32/shfldr_fs.c
@@ -1155,9 +1155,9 @@ ISFHelper_fnAddFolder (ISFHelper * iface, HWND hwnd, LPCWSTR pwszName,
 
         /* Cannot Create folder because of permissions */
         LoadStringW (shell32_hInstance, IDS_CREATEFOLDER_DENIED, wszTempText,
-         sizeof (wszTempText));
+         sizeof (wszTempText)/sizeof (wszTempText[0]));
         LoadStringW (shell32_hInstance, IDS_CREATEFOLDER_CAPTION, wszCaption,
-         sizeof (wszCaption));
+         sizeof (wszCaption)/sizeof (wszCaption[0]));
         sprintfW (wszText, wszTempText, wszNewDir);
         MessageBoxW (hwnd, wszText, wszCaption, MB_OK | MB_ICONEXCLAMATION);
     }