diff --git a/include/wx/msw/private.h b/include/wx/msw/private.h
index 96362e4a1b..4e954904b5 100644
--- a/include/wx/msw/private.h
+++ b/include/wx/msw/private.h
@@ -386,6 +386,21 @@ inline RECT wxGetClientRect(HWND hwnd)
     return rect;
 }
 
+// Call MapWindowPoints() on a RECT: because a RECT is (intentionally) laid out
+// as 2 consecutive POINTs, the cast below is valid but we still prefer to hide
+// it in this function instead of writing it out in the rest of the code.
+inline void wxMapWindowPoints(HWND hwndFrom, HWND hwndTo, RECT* rc)
+{
+    ::MapWindowPoints(hwndFrom, hwndTo, reinterpret_cast<POINT *>(rc), 2);
+}
+
+// For consistency also provide an overload taking a POINT, even if this one is
+// even more trivial.
+inline void wxMapWindowPoints(HWND hwndFrom, HWND hwndTo, POINT* pt)
+{
+    ::MapWindowPoints(hwndFrom, hwndTo, pt, 1);
+}
+
 // ---------------------------------------------------------------------------
 // small helper classes
 // ---------------------------------------------------------------------------
diff --git a/src/msw/msgdlg.cpp b/src/msw/msgdlg.cpp
index b239fd9024..f6103b7c16 100644
--- a/src/msw/msgdlg.cpp
+++ b/src/msw/msgdlg.cpp
@@ -87,10 +87,7 @@ wxMessageDialogMap& HookMap()
 void ScreenRectToClient(HWND hwnd, RECT& rc)
 {
     // map from desktop (i.e. screen) coordinates to ones of this window
-    //
-    // notice that a RECT is laid out as 2 consecutive POINTs so the cast is
-    // valid
-    ::MapWindowPoints(HWND_DESKTOP, hwnd, reinterpret_cast<POINT *>(&rc), 2);
+    wxMapWindowPoints(HWND_DESKTOP, hwnd, &rc);
 }
 
 // set window position to the given rect
diff --git a/src/msw/notebook.cpp b/src/msw/notebook.cpp
index caf75fa698..79617d4530 100644
--- a/src/msw/notebook.cpp
+++ b/src/msw/notebook.cpp
@@ -1195,7 +1195,7 @@ bool wxNotebook::MSWPrintChild(WXHDC hDC, wxWindow *child)
 
     // map rect to the coords of the window we're drawing in
     if ( child )
-        ::MapWindowPoints(GetHwnd(), GetHwndOf(child), (POINT *)&rc, 2);
+        wxMapWindowPoints(GetHwnd(), GetHwndOf(child), &rc);
 
     // If we're using a solid colour (for example if we've switched off
     // theming for this notebook), paint it
diff --git a/src/msw/treectrl.cpp b/src/msw/treectrl.cpp
index 83b5cf33a9..5c4cfbd408 100644
--- a/src/msw/treectrl.cpp
+++ b/src/msw/treectrl.cpp
@@ -3660,7 +3660,7 @@ bool wxTreeCtrl::MSWOnNotify(int idCtrl, WXLPARAM lParam, WXLPARAM *result)
                 POINT point;
                 point.x = GET_X_LPARAM(pos);
                 point.y = GET_Y_LPARAM(pos);
-                ::MapWindowPoints(HWND_DESKTOP, GetHwnd(), &point, 1);
+                wxMapWindowPoints(HWND_DESKTOP, GetHwnd(), &point);
                 int htFlags = 0;
                 wxTreeItemId item = HitTest(wxPoint(point.x, point.y), htFlags);
 
diff --git a/src/msw/window.cpp b/src/msw/window.cpp
index 07f150afe8..ec87aa140c 100644
--- a/src/msw/window.cpp
+++ b/src/msw/window.cpp
@@ -1950,8 +1950,9 @@ void wxWindowMSW::DoGetPosition(int *x, int *y) const
         {
             // In RTL mode, we want the logical left x-coordinate,
             // which would be the physical right x-coordinate.
-            ::MapWindowPoints(nullptr, parent ? GetHwndOf(parent) : HWND_DESKTOP,
-                              (LPPOINT)&rect, 2);
+            wxMapWindowPoints(HWND_DESKTOP,
+                              parent ? GetHwndOf(parent) : HWND_DESKTOP,
+                              &rect);
         }
 
         pos.x = rect.left;
@@ -5456,7 +5457,7 @@ wxWindowMSW::MSWGetBgBrushForChild(WXHDC hDC, wxWindowMSW *child)
         // uses RTL layout, which is exactly what we need here as the child
         // window origin is its _right_ top corner in this case and not the
         // left one.
-        ::MapWindowPoints(nullptr, GetHwnd(), (POINT *)&rc, 2);
+        wxMapWindowPoints(HWND_DESKTOP, GetHwnd(), &rc);
 
         int x = rc.left,
             y = rc.top;