diff --git a/dlls/uxtheme/dialog.c b/dlls/uxtheme/dialog.c
index b91e20f0f33..706d170936e 100644
--- a/dlls/uxtheme/dialog.c
+++ b/dlls/uxtheme/dialog.c
@@ -129,7 +129,7 @@ LRESULT WINAPI UXTHEME_DefDlgProc(HWND hwnd, UINT msg, WPARAM wp, LPARAM lp, BOO
     case WM_ERASEBKGND:
     {
         dlgproc = (WNDPROC)GetWindowLongPtrW(hwnd, DWLP_DLGPROC);
-        lr = CallWindowProcW(dlgproc, hwnd, msg, wp, lp);
+        lr = LOWORD(CallWindowProcW(dlgproc, hwnd, msg, wp, lp));
         if (lr)
             return lr;