diff --git a/dll/win32/comctl32/button.c b/dll/win32/comctl32/button.c
index 095515c2775..1d047b24cf2 100644
--- a/dll/win32/comctl32/button.c
+++ b/dll/win32/comctl32/button.c
@@ -1667,7 +1667,7 @@ static void BUTTON_CheckAutoRadioButton( HWND hwnd )
     {
         if (!sibling) break;
 #ifdef __REACTOS__
-        if (SendMessageW( sibling, WM_GETDLGCODE, 0, 0 ) == (DLGC_BUTTON | DLGC_RADIOBUTTON))
+        if ((SendMessageW( sibling, WM_GETDLGCODE, 0, 0 ) & (DLGC_BUTTON | DLGC_RADIOBUTTON)) == (DLGC_BUTTON | DLGC_RADIOBUTTON))
             SendMessageW( sibling, BM_SETCHECK, sibling == hwnd ? BST_CHECKED : BST_UNCHECKED, 0 );
 #else
         if ((hwnd != sibling) &&
diff --git a/win32ss/user/user32/controls/button.c b/win32ss/user/user32/controls/button.c
index 69377a96b2d..1cad76f161c 100644
--- a/win32ss/user/user32/controls/button.c
+++ b/win32ss/user/user32/controls/button.c
@@ -1196,7 +1196,7 @@ static void BUTTON_CheckAutoRadioButton( HWND hwnd )
     do
     {
         if (!sibling) break;
-        if (SendMessageW( sibling, WM_GETDLGCODE, 0, 0 ) == (DLGC_BUTTON | DLGC_RADIOBUTTON))
+        if ((SendMessageW( sibling, WM_GETDLGCODE, 0, 0 ) & (DLGC_BUTTON | DLGC_RADIOBUTTON)) == (DLGC_BUTTON | DLGC_RADIOBUTTON))
             SendMessageW( sibling, BM_SETCHECK, sibling == hwnd ? BST_CHECKED : BST_UNCHECKED, 0 );
         sibling = GetNextDlgGroupItem( parent, sibling, FALSE );
     } while (sibling != start);