diff --git a/dll/appcompat/apphelp/sdbapi.c b/dll/appcompat/apphelp/sdbapi.c
index 5ddf98938ca..28762d71ca0 100644
--- a/dll/appcompat/apphelp/sdbapi.c
+++ b/dll/appcompat/apphelp/sdbapi.c
@@ -414,7 +414,7 @@ BOOL WINAPI SdbGUIDToString(CONST GUID *Guid, PWSTR GuidString, SIZE_T Length)
     UNICODE_STRING GuidString_u;
     if (NT_SUCCESS(RtlStringFromGUID(Guid, &GuidString_u)))
     {
-        HRESULT hr = StringCchCopyNW(GuidString, Length, GuidString_u.Buffer, GuidString_u.Length / 2);
+        HRESULT hr = StringCchCopyNW(GuidString, Length, GuidString_u.Buffer, GuidString_u.Length / sizeof(WCHAR));
         RtlFreeUnicodeString(&GuidString_u);
         return SUCCEEDED(hr);
     }