win32ss/user/ntuser/winpos.c | 7 +++++++
 1 file changed, 7 insertions(+)

diff --git a/win32ss/user/ntuser/winpos.c b/win32ss/user/ntuser/winpos.c
index 7795f0293b6..4a602a49f89 100644
--- a/win32ss/user/ntuser/winpos.c
+++ b/win32ss/user/ntuser/winpos.c
@@ -999,6 +999,13 @@ co_WinPosGetMinMaxInfo(PWND Window, POINT* MaxSize, POINT* MaxPos,
 
     co_IntSendMessage(Window->head.h, WM_GETMINMAXINFO, 0, (LPARAM)&MinMax);
 
+    /* Validate returned MinMax */
+    if (MinMax.ptMaxTrackSize.x > 0)
+        MinMax.ptMaxTrackSize.x = min(MinMax.ptMaxTrackSize.x, UserGetSystemMetrics(SM_CXSCREEN));
+    
+    if (MinMax.ptMaxTrackSize.y > 0)
+        MinMax.ptMaxTrackSize.y = min(MinMax.ptMaxTrackSize.y, UserGetSystemMetrics(SM_CYSCREEN));
+
     /* if the app didn't change the values, adapt them for the current monitor */
     if ((monitor = UserGetPrimaryMonitor()))
     {