diff --git a/win32ss/user/ntuser/winpos.c b/win32ss/user/ntuser/winpos.c
index 4586d23..a160976 100644
--- a/win32ss/user/ntuser/winpos.c
+++ b/win32ss/user/ntuser/winpos.c
@@ -2100,12 +2100,11 @@ co_WinPosSetWindowPos(
 
                 if ( (Window->style & WS_CHILD) && (Parent) && !(Parent->style & WS_CLIPCHILDREN))
                 {
-                   IntInvalidateWindows( Parent, DirtyRgn, RDW_ERASE | RDW_INVALIDATE);
-                   co_IntPaintWindows(Parent, RDW_NOCHILDREN, FALSE);
+                   IntInvalidateWindows(Parent, DirtyRgn, RDW_ERASE | RDW_INVALIDATE | RDW_ALLCHILDREN); // This fixes CORE-12342 and CORE-15917
                 }
                 else
                 {
-                   IntInvalidateWindows( Window, DirtyRgn, RDW_ERASE | RDW_FRAME | RDW_INVALIDATE | RDW_ALLCHILDREN);
+                   IntInvalidateWindows(Window, DirtyRgn, RDW_ERASE | RDW_INVALIDATE | RDW_ALLCHILDREN | RDW_FRAME);
                 }
              }
              else if ( RgnType != ERROR && RgnType == NULLREGION ) // Must be the same. See CORE-7166 & CORE-15934, NC HACK fix.