diff --git a/reactos/dll/win32/user32/windows/clipboard.c b/reactos/dll/win32/user32/windows/clipboard.c
index 42515c1c3ae..6fb5ba34d88 100644
--- a/reactos/dll/win32/user32/windows/clipboard.c
+++ b/reactos/dll/win32/user32/windows/clipboard.c
@@ -135,9 +135,9 @@ GetClipboardFormatNameA(UINT format, LPSTR lpszFormatName, int cchMaxCount)
        if (!WideCharToMultiByte(CP_ACP, 0, lpBuffer, Length, lpszFormatName, cchMaxCount, NULL, NULL))
        {
           /* clear result string */
-          lpszFormatName[0] = '\0';
           Length = 0;
        }
+       lpszFormatName[Length] = '\0';
    }
 
    RtlFreeHeap(RtlGetProcessHeap(), 0, lpBuffer);