diff --git a/dlls/user32/combo.c b/dlls/user32/combo.c
index 7fc75e8038a..c4fe24cd61f 100644
--- a/dlls/user32/combo.c
+++ b/dlls/user32/combo.c
@@ -1001,7 +1001,7 @@ static void CBDropDown( LPHEADCOMBO lphc )
 
 
    if( !(lphc->wState & CBF_NOREDRAW) )
-     RedrawWindow( lphc->self, NULL, 0, RDW_INVALIDATE | RDW_ERASE | RDW_UPDATENOW );
+     NtUserRedrawWindow( lphc->self, NULL, 0, RDW_INVALIDATE | RDW_ERASE | RDW_UPDATENOW );
 
    EnableWindow( lphc->hWndLBox, TRUE );
    if (GetCapture() != lphc->self)
@@ -1056,8 +1056,8 @@ static void CBRollUp( LPHEADCOMBO lphc, BOOL ok, BOOL bButton )
 	   }
 
 	   if( bButton && !(lphc->wState & CBF_NOREDRAW) )
-	       RedrawWindow( hWnd, &rect, 0, RDW_INVALIDATE |
-			       RDW_ERASE | RDW_UPDATENOW | RDW_NOCHILDREN );
+	       NtUserRedrawWindow( hWnd, &rect, 0, RDW_INVALIDATE |
+                                   RDW_ERASE | RDW_UPDATENOW | RDW_NOCHILDREN );
 	   CB_NOTIFY( lphc, CBN_CLOSEUP );
        }
    }
@@ -1423,7 +1423,7 @@ static void CBResetPos(HEADCOMBO *combo, BOOL redraw)
         }
 
         if (redraw && !(combo->wState & CBF_NOREDRAW))
-            RedrawWindow(combo->self, NULL, 0, RDW_INVALIDATE | RDW_ERASE | RDW_UPDATENOW);
+            NtUserRedrawWindow( combo->self, NULL, 0, RDW_INVALIDATE | RDW_ERASE | RDW_UPDATENOW );
     }
 }
 
diff --git a/dlls/user32/defwnd.c b/dlls/user32/defwnd.c
index c4de8928462..f9f9fa056a4 100644
--- a/dlls/user32/defwnd.c
+++ b/dlls/user32/defwnd.c
@@ -387,14 +387,14 @@ static LRESULT DEFWND_DefWinProc( HWND hwnd, UINT msg, WPARAM wParam, LPARAM lPa
         }
 
     case WM_SYNCPAINT:
-        RedrawWindow ( hwnd, NULL, 0, RDW_ERASENOW | RDW_ERASE | RDW_ALLCHILDREN );
+        NtUserRedrawWindow ( hwnd, NULL, 0, RDW_ERASENOW | RDW_ERASE | RDW_ALLCHILDREN );
         return 0;
 
     case WM_SETREDRAW:
         if (wParam) WIN_SetStyle( hwnd, WS_VISIBLE, 0 );
         else
         {
-            RedrawWindow( hwnd, NULL, 0, RDW_ALLCHILDREN | RDW_VALIDATE );
+            NtUserRedrawWindow( hwnd, NULL, 0, RDW_ALLCHILDREN | RDW_VALIDATE );
             WIN_SetStyle( hwnd, 0, WS_VISIBLE );
         }
         return 0;
diff --git a/dlls/user32/desktop.c b/dlls/user32/desktop.c
index e1cd6985ad3..9d1484fdcbb 100644
--- a/dlls/user32/desktop.c
+++ b/dlls/user32/desktop.c
@@ -219,6 +219,6 @@ BOOL update_wallpaper( const WCHAR *wallpaper, const WCHAR *pattern )
         }
     }
     init_wallpaper( wallpaper );
-    RedrawWindow( GetDesktopWindow(), 0, 0, RDW_INVALIDATE | RDW_ERASE | RDW_NOCHILDREN );
+    NtUserRedrawWindow( GetDesktopWindow(), 0, 0, RDW_INVALIDATE | RDW_ERASE | RDW_NOCHILDREN );
     return TRUE;
 }
diff --git a/dlls/user32/menu.c b/dlls/user32/menu.c
index c0d03d30d0f..28fe35cc917 100644
--- a/dlls/user32/menu.c
+++ b/dlls/user32/menu.c
@@ -3751,7 +3751,7 @@ BOOL WINAPI EnableMenuItem( HMENU hMenu, UINT id, UINT wFlags )
         /* Refresh the frame to reflect the change */
         WIN_GetRectangles(hwnd, COORDS_CLIENT, &rc, NULL);
         rc.bottom = 0;
-        RedrawWindow(hwnd, &rc, 0, RDW_FRAME | RDW_INVALIDATE | RDW_NOCHILDREN);
+        NtUserRedrawWindow( hwnd, &rc, 0, RDW_FRAME | RDW_INVALIDATE | RDW_NOCHILDREN );
     }
     else
         release_menu_ptr(menu);
diff --git a/dlls/user32/painting.c b/dlls/user32/painting.c
index 218f57f1670..336340c75a9 100644
--- a/dlls/user32/painting.c
+++ b/dlls/user32/painting.c
@@ -35,45 +35,6 @@
 WINE_DEFAULT_DEBUG_CHANNEL(win);
 
 
-/***********************************************************************
- *           dump_rdw_flags
- */
-static void dump_rdw_flags(UINT flags)
-{
-    TRACE("flags:");
-    if (flags & RDW_INVALIDATE) TRACE(" RDW_INVALIDATE");
-    if (flags & RDW_INTERNALPAINT) TRACE(" RDW_INTERNALPAINT");
-    if (flags & RDW_ERASE) TRACE(" RDW_ERASE");
-    if (flags & RDW_VALIDATE) TRACE(" RDW_VALIDATE");
-    if (flags & RDW_NOINTERNALPAINT) TRACE(" RDW_NOINTERNALPAINT");
-    if (flags & RDW_NOERASE) TRACE(" RDW_NOERASE");
-    if (flags & RDW_NOCHILDREN) TRACE(" RDW_NOCHILDREN");
-    if (flags & RDW_ALLCHILDREN) TRACE(" RDW_ALLCHILDREN");
-    if (flags & RDW_UPDATENOW) TRACE(" RDW_UPDATENOW");
-    if (flags & RDW_ERASENOW) TRACE(" RDW_ERASENOW");
-    if (flags & RDW_FRAME) TRACE(" RDW_FRAME");
-    if (flags & RDW_NOFRAME) TRACE(" RDW_NOFRAME");
-
-#define RDW_FLAGS \
-    (RDW_INVALIDATE | \
-    RDW_INTERNALPAINT | \
-    RDW_ERASE | \
-    RDW_VALIDATE | \
-    RDW_NOINTERNALPAINT | \
-    RDW_NOERASE | \
-    RDW_NOCHILDREN | \
-    RDW_ALLCHILDREN | \
-    RDW_UPDATENOW | \
-    RDW_ERASENOW | \
-    RDW_FRAME | \
-    RDW_NOFRAME)
-
-    if (flags & ~RDW_FLAGS) TRACE(" %04x", flags & ~RDW_FLAGS);
-    TRACE("\n");
-#undef RDW_FLAGS
-}
-
-
 /***********************************************************************
  *           free_dce
  *
@@ -221,30 +182,6 @@ static BOOL get_update_flags( HWND hwnd, HWND *child, UINT *flags )
 }
 
 
-/***********************************************************************
- *           redraw_window_rects
- *
- * Redraw part of a window.
- */
-static BOOL redraw_window_rects( HWND hwnd, UINT flags, const RECT *rects, UINT count )
-{
-    BOOL ret;
-
-    if (!(flags & (RDW_INVALIDATE|RDW_VALIDATE|RDW_INTERNALPAINT|RDW_NOINTERNALPAINT)))
-        return TRUE;  /* nothing to do */
-
-    SERVER_START_REQ( redraw_window )
-    {
-        req->window = wine_server_user_handle( hwnd );
-        req->flags  = flags;
-        wine_server_add_data( req, rects, count * sizeof(RECT) );
-        ret = !wine_server_call_err( req );
-    }
-    SERVER_END_REQ;
-    return ret;
-}
-
-
 /***********************************************************************
  *           send_ncpaint
  *
@@ -469,35 +406,6 @@ void move_window_bits_parent( HWND hwnd, HWND parent, const RECT *window_rect, c
 }
 
 
-/***********************************************************************
- *           update_now
- *
- * Implementation of RDW_UPDATENOW behavior.
- */
-static void update_now( HWND hwnd, UINT rdw_flags )
-{
-    HWND child = 0;
-
-    /* desktop window never gets WM_PAINT, only WM_ERASEBKGND */
-    if (hwnd == GetDesktopWindow()) erase_now( hwnd, rdw_flags | RDW_NOCHILDREN );
-
-    /* loop while we find a child to repaint */
-    for (;;)
-    {
-        UINT flags = UPDATE_PAINT | UPDATE_INTERNALPAINT;
-
-        if (rdw_flags & RDW_NOCHILDREN) flags |= UPDATE_NOCHILDREN;
-        else if (rdw_flags & RDW_ALLCHILDREN) flags |= UPDATE_ALLCHILDREN;
-
-        if (!get_update_flags( hwnd, &child, &flags )) break;
-        if (!flags) break;  /* nothing more to do */
-
-        SendMessageW( child, WM_PAINT, 0, 0 );
-        if (rdw_flags & RDW_NOCHILDREN) break;
-    }
-}
-
-
 /*************************************************************************
  *             fix_caret
  *
@@ -618,66 +526,6 @@ BOOL WINAPI LockWindowUpdate( HWND hwnd )
 }
 
 
-/***********************************************************************
- *		RedrawWindow (USER32.@)
- */
-BOOL WINAPI RedrawWindow( HWND hwnd, const RECT *rect, HRGN hrgn, UINT flags )
-{
-    static const RECT empty;
-    BOOL ret;
-
-    if (TRACE_ON(win))
-    {
-        if (hrgn)
-        {
-            RECT r;
-            GetRgnBox( hrgn, &r );
-            TRACE( "%p region %p box %s ", hwnd, hrgn, wine_dbgstr_rect(&r) );
-        }
-        else if (rect)
-            TRACE( "%p rect %s ", hwnd, wine_dbgstr_rect(rect) );
-        else
-            TRACE( "%p whole window ", hwnd );
-
-        dump_rdw_flags(flags);
-    }
-
-    /* process pending expose events before painting */
-    if (flags & RDW_UPDATENOW) USER_Driver->pMsgWaitForMultipleObjectsEx( 0, NULL, 0, QS_PAINT, 0 );
-
-    if (rect && !hrgn)
-    {
-        if (IsRectEmpty( rect )) rect = ∅
-        ret = redraw_window_rects( hwnd, flags, rect, 1 );
-    }
-    else if (!hrgn)
-    {
-        ret = redraw_window_rects( hwnd, flags, NULL, 0 );
-    }
-    else  /* need to build a list of the region rectangles */
-    {
-        DWORD size;
-        RGNDATA *data;
-
-        if (!(size = GetRegionData( hrgn, 0, NULL ))) return FALSE;
-        if (!(data = HeapAlloc( GetProcessHeap(), 0, size ))) return FALSE;
-        GetRegionData( hrgn, size, data );
-        if (!data->rdh.nCount)  /* empty region -> use a single all-zero rectangle */
-            ret = redraw_window_rects( hwnd, flags, &empty, 1 );
-        else
-            ret = redraw_window_rects( hwnd, flags, (const RECT *)data->Buffer, data->rdh.nCount );
-        HeapFree( GetProcessHeap(), 0, data );
-    }
-
-    if (!hwnd) hwnd = GetDesktopWindow();
-
-    if (flags & RDW_UPDATENOW) update_now( hwnd, flags );
-    else if (flags & RDW_ERASENOW) erase_now( hwnd, flags );
-
-    return ret;
-}
-
-
 /***********************************************************************
  *		UpdateWindow (USER32.@)
  */
@@ -689,7 +537,7 @@ BOOL WINAPI UpdateWindow( HWND hwnd )
         return FALSE;
     }
 
-    return RedrawWindow( hwnd, NULL, 0, RDW_UPDATENOW | RDW_ALLCHILDREN );
+    return NtUserRedrawWindow( hwnd, NULL, 0, RDW_UPDATENOW | RDW_ALLCHILDREN );
 }
 
 
@@ -704,7 +552,7 @@ BOOL WINAPI InvalidateRgn( HWND hwnd, HRGN hrgn, BOOL erase )
         return FALSE;
     }
 
-    return RedrawWindow(hwnd, NULL, hrgn, RDW_INVALIDATE | (erase ? RDW_ERASE : 0) );
+    return NtUserRedrawWindow( hwnd, NULL, hrgn, RDW_INVALIDATE | (erase ? RDW_ERASE : 0) );
 }
 
 
@@ -724,7 +572,7 @@ BOOL WINAPI InvalidateRect( HWND hwnd, const RECT *rect, BOOL erase )
         rect = NULL;
     }
 
-    return RedrawWindow( hwnd, rect, 0, flags );
+    return NtUserRedrawWindow( hwnd, rect, 0, flags );
 }
 
 
@@ -739,7 +587,7 @@ BOOL WINAPI ValidateRgn( HWND hwnd, HRGN hrgn )
         return FALSE;
     }
 
-    return RedrawWindow( hwnd, NULL, hrgn, RDW_VALIDATE );
+    return NtUserRedrawWindow( hwnd, NULL, hrgn, RDW_VALIDATE );
 }
 
 
@@ -759,7 +607,7 @@ BOOL WINAPI ValidateRect( HWND hwnd, const RECT *rect )
         rect = NULL;
     }
 
-    return RedrawWindow( hwnd, rect, 0, flags );
+    return NtUserRedrawWindow( hwnd, rect, 0, flags );
 }
 
 
@@ -917,7 +765,7 @@ static INT scroll_window( HWND hwnd, INT dx, INT dy, const RECT *rect, const REC
             NtUserReleaseDC( hwnd, hDC );
 
             if (!bUpdate)
-                RedrawWindow( hwnd, NULL, hrgnUpdate, rdw_flags);
+                NtUserRedrawWindow( hwnd, NULL, hrgnUpdate, rdw_flags);
         }
 
         /* If the windows has an update region, this must be
@@ -936,7 +784,7 @@ static INT scroll_window( HWND hwnd, INT dx, INT dy, const RECT *rect, const REC
             CombineRgn( hrgnTemp, hrgnTemp, hrgnClip, RGN_AND );
             if( !bOwnRgn)
                 CombineRgn( hrgnWinupd, hrgnWinupd, hrgnTemp, RGN_OR );
-            RedrawWindow( hwnd, NULL, hrgnTemp, rdw_flags);
+            NtUserRedrawWindow( hwnd, NULL, hrgnTemp, rdw_flags);
 
            /* Catch the case where the scrolling amount exceeds the size of the
             * original window. This generated a second update area that is the
@@ -993,8 +841,8 @@ static INT scroll_window( HWND hwnd, INT dx, INT dy, const RECT *rect, const REC
     }
 
     if( flags & (SW_INVALIDATE | SW_ERASE) )
-        RedrawWindow( hwnd, NULL, hrgnUpdate, rdw_flags |
-                      ((flags & SW_SCROLLCHILDREN) ? RDW_ALLCHILDREN : 0 ) );
+        NtUserRedrawWindow( hwnd, NULL, hrgnUpdate, rdw_flags |
+                            ((flags & SW_SCROLLCHILDREN) ? RDW_ALLCHILDREN : 0 ) );
 
     if( hrgnWinupd) {
         CombineRgn( hrgnUpdate, hrgnUpdate, hrgnWinupd, RGN_OR);
diff --git a/dlls/user32/static.c b/dlls/user32/static.c
index 013e5c20312..44107dbd52c 100644
--- a/dlls/user32/static.c
+++ b/dlls/user32/static.c
@@ -473,7 +473,8 @@ LRESULT StaticWndProc_common( HWND hwnd, UINT uMsg, WPARAM wParam, LPARAM lParam
         {
             SetWindowLongPtrW( hwnd, HFONT_GWL_OFFSET, wParam );
             if (LOWORD(lParam))
-                RedrawWindow( hwnd, NULL, 0, RDW_INVALIDATE | RDW_ERASE | RDW_UPDATENOW | RDW_ALLCHILDREN );
+                NtUserRedrawWindow( hwnd, NULL, 0, RDW_INVALIDATE | RDW_ERASE |
+                                    RDW_UPDATENOW | RDW_ALLCHILDREN );
         }
         break;
 
diff --git a/dlls/user32/user32.spec b/dlls/user32/user32.spec
index 8b339f7bfac..143eee5f4d1 100644
--- a/dlls/user32/user32.spec
+++ b/dlls/user32/user32.spec
@@ -590,7 +590,7 @@
 # @ stub ReasonCodeNeedsBugID
 # @ stub ReasonCodeNeedsComment
 # @ stub RecordShutdownReason
-@ stdcall RedrawWindow(long ptr long long)
+@ stdcall RedrawWindow(long ptr long long) NtUserRedrawWindow
 @ stdcall RegisterClassA(ptr)
 @ stdcall RegisterClassExA(ptr)
 @ stdcall RegisterClassExW(ptr)
diff --git a/dlls/user32/user_main.c b/dlls/user32/user_main.c
index 1b4e8833a89..68c8fc7eada 100644
--- a/dlls/user32/user_main.c
+++ b/dlls/user32/user_main.c
@@ -145,7 +145,6 @@ static const struct user_callbacks user_funcs =
     CopyImage,
     HideCaret,
     PostMessageW,
-    RedrawWindow,
     SendInput,
     SendMessageTimeoutW,
     SendMessageW,
diff --git a/dlls/user32/winpos.c b/dlls/user32/winpos.c
index e7b90f60355..dd3cd57132a 100644
--- a/dlls/user32/winpos.c
+++ b/dlls/user32/winpos.c
@@ -2735,7 +2735,7 @@ void WINPOS_SysCommandSizeMove( HWND hwnd, WPARAM wParam )
     if (parent) SystemParametersInfoW( SPI_GETDRAGFULLWINDOWS, 0, &DragFullWindows, 0 );
 
     /* repaint the window before moving it around */
-    RedrawWindow( hwnd, NULL, 0, RDW_UPDATENOW | RDW_ALLCHILDREN );
+    NtUserRedrawWindow( hwnd, NULL, 0, RDW_UPDATENOW | RDW_ALLCHILDREN );
 
     SendMessageW( hwnd, WM_ENTERSIZEMOVE, 0, 0 );
     set_capture_window( hwnd, GUI_INMOVESIZE, NULL );
diff --git a/dlls/win32u/dce.c b/dlls/win32u/dce.c
index 218f502f848..d3a69aa0763 100644
--- a/dlls/win32u/dce.c
+++ b/dlls/win32u/dce.c
@@ -146,6 +146,44 @@ done:
     pthread_mutex_unlock( &surfaces_lock );
 }
 
+/***********************************************************************
+ *           dump_rdw_flags
+ */
+static void dump_rdw_flags(UINT flags)
+{
+    TRACE("flags:");
+    if (flags & RDW_INVALIDATE) TRACE(" RDW_INVALIDATE");
+    if (flags & RDW_INTERNALPAINT) TRACE(" RDW_INTERNALPAINT");
+    if (flags & RDW_ERASE) TRACE(" RDW_ERASE");
+    if (flags & RDW_VALIDATE) TRACE(" RDW_VALIDATE");
+    if (flags & RDW_NOINTERNALPAINT) TRACE(" RDW_NOINTERNALPAINT");
+    if (flags & RDW_NOERASE) TRACE(" RDW_NOERASE");
+    if (flags & RDW_NOCHILDREN) TRACE(" RDW_NOCHILDREN");
+    if (flags & RDW_ALLCHILDREN) TRACE(" RDW_ALLCHILDREN");
+    if (flags & RDW_UPDATENOW) TRACE(" RDW_UPDATENOW");
+    if (flags & RDW_ERASENOW) TRACE(" RDW_ERASENOW");
+    if (flags & RDW_FRAME) TRACE(" RDW_FRAME");
+    if (flags & RDW_NOFRAME) TRACE(" RDW_NOFRAME");
+
+#define RDW_FLAGS \
+    (RDW_INVALIDATE | \
+     RDW_INTERNALPAINT | \
+     RDW_ERASE | \
+     RDW_VALIDATE | \
+     RDW_NOINTERNALPAINT | \
+     RDW_NOERASE | \
+     RDW_NOCHILDREN | \
+     RDW_ALLCHILDREN | \
+     RDW_UPDATENOW | \
+     RDW_ERASENOW | \
+     RDW_FRAME | \
+     RDW_NOFRAME)
+
+    if (flags & ~RDW_FLAGS) TRACE(" %04x", flags & ~RDW_FLAGS);
+    TRACE("\n");
+#undef RDW_FLAGS
+}
+
 /***********************************************************************
  *           update_visible_region
  *
@@ -790,6 +828,53 @@ static HRGN get_update_region( HWND hwnd, UINT *flags, HWND *child )
     return hrgn;
 }
 
+/***********************************************************************
+ *           redraw_window_rects
+ *
+ * Redraw part of a window.
+ */
+static BOOL redraw_window_rects( HWND hwnd, UINT flags, const RECT *rects, UINT count )
+{
+    BOOL ret;
+
+    if (!(flags & (RDW_INVALIDATE|RDW_VALIDATE|RDW_INTERNALPAINT|RDW_NOINTERNALPAINT)))
+        return TRUE;  /* nothing to do */
+
+    SERVER_START_REQ( redraw_window )
+    {
+        req->window = wine_server_user_handle( hwnd );
+        req->flags  = flags;
+        wine_server_add_data( req, rects, count * sizeof(RECT) );
+        ret = !wine_server_call_err( req );
+    }
+    SERVER_END_REQ;
+    return ret;
+}
+
+/***********************************************************************
+ *           get_update_flags
+ *
+ * Get only the update flags, not the update region.
+ */
+static BOOL get_update_flags( HWND hwnd, HWND *child, UINT *flags )
+{
+    BOOL ret;
+
+    SERVER_START_REQ( get_update_region )
+    {
+        req->window     = wine_server_user_handle( hwnd );
+        req->from_child = wine_server_user_handle( child ? *child : 0 );
+        req->flags      = *flags | UPDATE_NOREGION;
+        if ((ret = !wine_server_call_err( req )))
+        {
+            if (child) *child = wine_server_ptr_handle( reply->child );
+            *flags = reply->flags;
+        }
+    }
+    SERVER_END_REQ;
+    return ret;
+}
+
 /***********************************************************************
  *           send_ncpaint
  *
@@ -938,3 +1023,118 @@ BOOL WINAPI NtUserEndPaint( HWND hwnd, const PAINTSTRUCT *ps )
     release_dc( hwnd, ps->hdc, TRUE );
     return TRUE;
 }
+
+/***********************************************************************
+ *           erase_now
+ *
+ * Implementation of RDW_ERASENOW behavior.
+ */
+void erase_now( HWND hwnd, UINT rdw_flags )
+{
+    HWND child = 0;
+    HRGN hrgn;
+    BOOL need_erase = FALSE;
+
+    /* loop while we find a child to repaint */
+    for (;;)
+    {
+        UINT flags = UPDATE_NONCLIENT | UPDATE_ERASE;
+
+        if (rdw_flags & RDW_NOCHILDREN) flags |= UPDATE_NOCHILDREN;
+        else if (rdw_flags & RDW_ALLCHILDREN) flags |= UPDATE_ALLCHILDREN;
+        if (need_erase) flags |= UPDATE_DELAYED_ERASE;
+
+        if (!(hrgn = send_ncpaint( hwnd, &child, &flags ))) break;
+        need_erase = send_erase( child, flags, hrgn, NULL, NULL );
+
+        if (!flags) break;  /* nothing more to do */
+        if ((rdw_flags & RDW_NOCHILDREN) && !need_erase) break;
+    }
+}
+
+/***********************************************************************
+ *           update_now
+ *
+ * Implementation of RDW_UPDATENOW behavior.
+ */
+static void update_now( HWND hwnd, UINT rdw_flags )
+{
+    HWND child = 0;
+
+    /* desktop window never gets WM_PAINT, only WM_ERASEBKGND */
+    if (hwnd == get_desktop_window()) erase_now( hwnd, rdw_flags | RDW_NOCHILDREN );
+
+    /* loop while we find a child to repaint */
+    for (;;)
+    {
+        UINT flags = UPDATE_PAINT | UPDATE_INTERNALPAINT;
+
+        if (rdw_flags & RDW_NOCHILDREN) flags |= UPDATE_NOCHILDREN;
+        else if (rdw_flags & RDW_ALLCHILDREN) flags |= UPDATE_ALLCHILDREN;
+
+        if (!get_update_flags( hwnd, &child, &flags )) break;
+        if (!flags) break;  /* nothing more to do */
+
+        send_message( child, WM_PAINT, 0, 0 );
+        if (rdw_flags & RDW_NOCHILDREN) break;
+    }
+}
+
+/***********************************************************************
+ *           NtUserRedrawWindow (win32u.@)
+ */
+BOOL WINAPI NtUserRedrawWindow( HWND hwnd, const RECT *rect, HRGN hrgn, UINT flags )
+{
+    static const RECT empty;
+    BOOL ret;
+
+    if (TRACE_ON(win))
+    {
+        if (hrgn)
+        {
+            RECT r;
+            NtGdiGetRgnBox( hrgn, &r );
+            TRACE( "%p region %p box %s ", hwnd, hrgn, wine_dbgstr_rect(&r) );
+        }
+        else if (rect)
+            TRACE( "%p rect %s ", hwnd, wine_dbgstr_rect(rect) );
+        else
+            TRACE( "%p whole window ", hwnd );
+
+        dump_rdw_flags(flags);
+    }
+
+    /* process pending expose events before painting */
+    if (flags & RDW_UPDATENOW) user_driver->pMsgWaitForMultipleObjectsEx( 0, NULL, 0, QS_PAINT, 0 );
+
+    if (rect && !hrgn)
+    {
+        if (IsRectEmpty( rect )) rect = ∅
+        ret = redraw_window_rects( hwnd, flags, rect, 1 );
+    }
+    else if (!hrgn)
+    {
+        ret = redraw_window_rects( hwnd, flags, NULL, 0 );
+    }
+    else  /* need to build a list of the region rectangles */
+    {
+        DWORD size;
+        RGNDATA *data;
+
+        if (!(size = NtGdiGetRegionData( hrgn, 0, NULL ))) return FALSE;
+        if (!(data = malloc( size ))) return FALSE;
+        NtGdiGetRegionData( hrgn, size, data );
+        if (!data->rdh.nCount)  /* empty region -> use a single all-zero rectangle */
+            ret = redraw_window_rects( hwnd, flags, &empty, 1 );
+        else
+            ret = redraw_window_rects( hwnd, flags, (const RECT *)data->Buffer, data->rdh.nCount );
+        free( data );
+    }
+
+    if (!hwnd) hwnd = get_desktop_window();
+
+    if (flags & RDW_UPDATENOW) update_now( hwnd, flags );
+    else if (flags & RDW_ERASENOW) erase_now( hwnd, flags );
+
+    return ret;
+}
diff --git a/dlls/win32u/gdiobj.c b/dlls/win32u/gdiobj.c
index 68cde8936a3..689813a724c 100644
--- a/dlls/win32u/gdiobj.c
+++ b/dlls/win32u/gdiobj.c
@@ -1181,6 +1181,7 @@ static struct unix_funcs unix_funcs =
     NtUserIsClipboardFormatAvailable,
     NtUserMapVirtualKeyEx,
     NtUserMoveWindow,
+    NtUserRedrawWindow,
     NtUserRegisterClassExWOW,
     NtUserRegisterHotKey,
     NtUserReleaseDC,
diff --git a/dlls/win32u/ntuser_private.h b/dlls/win32u/ntuser_private.h
index 0e73be6fcd0..4d3e0fe5bf0 100644
--- a/dlls/win32u/ntuser_private.h
+++ b/dlls/win32u/ntuser_private.h
@@ -32,7 +32,6 @@ struct user_callbacks
     HANDLE (WINAPI *pCopyImage)( HANDLE, UINT, INT, INT, UINT );
     BOOL (WINAPI *pHideCaret)( HWND hwnd );
     BOOL (WINAPI *pPostMessageW)( HWND, UINT, WPARAM, LPARAM );
-    BOOL (WINAPI *pRedrawWindow)( HWND, const RECT*, HRGN, UINT );
     UINT (WINAPI *pSendInput)( UINT count, INPUT *inputs, int size );
     LRESULT (WINAPI *pSendMessageTimeoutW)( HWND, UINT, WPARAM, LPARAM, UINT, UINT, PDWORD_PTR );
     LRESULT (WINAPI *pSendMessageW)( HWND, UINT, WPARAM, LPARAM );
diff --git a/dlls/win32u/palette.c b/dlls/win32u/palette.c
index 18885c7fba8..2a394ba7eba 100644
--- a/dlls/win32u/palette.c
+++ b/dlls/win32u/palette.c
@@ -602,14 +602,13 @@ BOOL WINAPI NtGdiUpdateColors( HDC hDC )
     HWND hwnd;
 
     if (!size) return FALSE;
-    if (!user_callbacks) return TRUE;
 
     hwnd = NtUserWindowFromDC( hDC );
 
     /* Docs say that we have to remap current drawable pixel by pixel
      * but it would take forever given the speed of XGet/PutPixel.
      */
-    if (hwnd && size) user_callbacks->pRedrawWindow( hwnd, NULL, 0, RDW_INVALIDATE );
+    if (hwnd && size) NtUserRedrawWindow( hwnd, NULL, 0, RDW_INVALIDATE );
     return TRUE;
 }
 
diff --git a/dlls/win32u/sysparams.c b/dlls/win32u/sysparams.c
index f72b071ed9e..ea96a704776 100644
--- a/dlls/win32u/sysparams.c
+++ b/dlls/win32u/sysparams.c
@@ -4540,8 +4540,7 @@ BOOL WINAPI NtUserSetSysColors( INT count, const INT *colors, const COLORREF *va
     user_callbacks->pSendMessageTimeoutW( HWND_BROADCAST, WM_SYSCOLORCHANGE, 0, 0,
                                           SMTO_ABORTIFHUNG, 2000, NULL );
     /* Repaint affected portions of all visible windows */
-    user_callbacks->pRedrawWindow( 0, NULL, 0, RDW_INVALIDATE | RDW_ERASE | RDW_UPDATENOW |
-                                   RDW_ALLCHILDREN );
+    NtUserRedrawWindow( 0, NULL, 0, RDW_INVALIDATE | RDW_ERASE | RDW_UPDATENOW | RDW_ALLCHILDREN );
     return TRUE;
 }
 
diff --git a/dlls/win32u/win32u.spec b/dlls/win32u/win32u.spec
index ad24113adff..882759a9802 100644
--- a/dlls/win32u/win32u.spec
+++ b/dlls/win32u/win32u.spec
@@ -1120,7 +1120,7 @@
 @ stub NtUserRealChildWindowFromPoint
 @ stub NtUserRealInternalGetMessage
 @ stub NtUserRealWaitMessageEx
-@ stub NtUserRedrawWindow
+@ stdcall NtUserRedrawWindow(long ptr long long)
 @ stub NtUserRegisterBSDRWindow
 @ stdcall NtUserRegisterClassExWOW(ptr ptr ptr ptr long long long)
 @ stub NtUserRegisterDManipHook
diff --git a/dlls/win32u/win32u_private.h b/dlls/win32u/win32u_private.h
index b67a90c26c7..65b6f4df7b7 100644
--- a/dlls/win32u/win32u_private.h
+++ b/dlls/win32u/win32u_private.h
@@ -222,6 +222,7 @@ struct unix_funcs
     BOOL     (WINAPI *pNtUserIsClipboardFormatAvailable)( UINT format );
     UINT     (WINAPI *pNtUserMapVirtualKeyEx)( UINT code, UINT type, HKL layout );
     BOOL     (WINAPI *pNtUserMoveWindow)( HWND hwnd, INT x, INT y, INT cx, INT cy, BOOL repaint );
+    BOOL     (WINAPI *pNtUserRedrawWindow)( HWND hwnd, const RECT *rect, HRGN hrgn, UINT flags );
     ATOM     (WINAPI *pNtUserRegisterClassExWOW)( const WNDCLASSEXW *wc, UNICODE_STRING *name,
                                                   UNICODE_STRING *version,
                                                   struct client_menu_name *client_menu_name,
diff --git a/dlls/win32u/window.c b/dlls/win32u/window.c
index 0cd70cdca02..09a4d9cf3e7 100644
--- a/dlls/win32u/window.c
+++ b/dlls/win32u/window.c
@@ -1812,7 +1812,7 @@ BOOL WINAPI NtUserFlashWindowEx( FLASHWINFO *info )
 
     if (is_iconic( info->hwnd ))
     {
-        user_callbacks->pRedrawWindow( info->hwnd, 0, 0, RDW_INVALIDATE | RDW_ERASE | RDW_UPDATENOW | RDW_FRAME );
+        NtUserRedrawWindow( info->hwnd, 0, 0, RDW_INVALIDATE | RDW_ERASE | RDW_UPDATENOW | RDW_FRAME );
 
         win = get_win_ptr( info->hwnd );
         if (!win || win == WND_OTHER_PROCESS || win == WND_DESKTOP) return FALSE;
diff --git a/dlls/win32u/wrappers.c b/dlls/win32u/wrappers.c
index 40100c7cde2..452bde6683e 100644
--- a/dlls/win32u/wrappers.c
+++ b/dlls/win32u/wrappers.c
@@ -894,6 +894,12 @@ UINT WINAPI NtUserMapVirtualKeyEx( UINT code, UINT type, HKL layout )
     return unix_funcs->pNtUserMapVirtualKeyEx( code, type, layout );
 }
 
+BOOL WINAPI NtUserRedrawWindow( HWND hwnd, const RECT *rect, HRGN hrgn, UINT flags )
+{
+    if (!unix_funcs) return FALSE;
+    return unix_funcs->pNtUserRedrawWindow( hwnd, rect, hrgn, flags );
+}
+
 ATOM WINAPI NtUserRegisterClassExWOW( const WNDCLASSEXW *wc, UNICODE_STRING *name, UNICODE_STRING *version,
                                       struct client_menu_name *client_menu_name, DWORD fnid, DWORD flags,
                                       DWORD *wow )
diff --git a/include/ntuser.h b/include/ntuser.h
index e27ef262403..b0285b7418b 100644
--- a/include/ntuser.h
+++ b/include/ntuser.h
@@ -365,6 +365,7 @@ HWINSTA WINAPI NtUserOpenWindowStation( OBJECT_ATTRIBUTES *attr, ACCESS_MASK acc
 BOOL    WINAPI NtUserSetObjectInformation( HANDLE handle, INT index, void *info, DWORD len );
 HDESK   WINAPI NtUserOpenDesktop( OBJECT_ATTRIBUTES *attr, DWORD flags, ACCESS_MASK access );
 HDESK   WINAPI NtUserOpenInputDesktop( DWORD flags, BOOL inherit, ACCESS_MASK access );
+BOOL    WINAPI NtUserRedrawWindow( HWND hwnd, const RECT *rect, HRGN hrgn, UINT flags );
 ATOM    WINAPI NtUserRegisterClassExWOW( const WNDCLASSEXW *wc, UNICODE_STRING *name, UNICODE_STRING *version,
                                          struct client_menu_name *client_menu_name, DWORD fnid, DWORD flags,
                                          DWORD *wow );