diff --git a/reactos/dll/cpl/desk/monslctl.c b/reactos/dll/cpl/desk/monslctl.c
index 1cb9427a822..74390fcb717 100644
--- a/reactos/dll/cpl/desk/monslctl.c
+++ b/reactos/dll/cpl/desk/monslctl.c
@@ -1345,7 +1345,14 @@ MonitorSelWndProc(IN HWND hwnd,
 
         case WM_UPDATEUISTATE:
         {
-            DWORD OldUIState = infoPtr->UIState;
+            DWORD OldUIState;
+
+            Ret = DefWindowProcW(hwnd,
+                                 uMsg,
+                                 wParam,
+                                 lParam);
+
+            OldUIState = infoPtr->UIState;
             switch (LOWORD(wParam))
             {
                 case UIS_SET:
diff --git a/reactos/dll/cpl/timedate/monthcal.c b/reactos/dll/cpl/timedate/monthcal.c
index 6ef037d8c28..7d7faf96f4e 100644
--- a/reactos/dll/cpl/timedate/monthcal.c
+++ b/reactos/dll/cpl/timedate/monthcal.c
@@ -856,7 +856,14 @@ MonthCalWndProc(IN HWND hwnd,
 
         case WM_UPDATEUISTATE:
         {
-            DWORD OldUIState = infoPtr->UIState;
+            DWORD OldUIState;
+
+            Ret = DefWindowProcW(hwnd,
+                                 uMsg,
+                                 wParam,
+                                 lParam);
+
+            OldUIState = infoPtr->UIState;
             switch (LOWORD(wParam))
             {
                 case UIS_SET: