diff --git a/dlls/user32/tests/msg.c b/dlls/user32/tests/msg.c
index 0b63799aed4..32087519996 100644
--- a/dlls/user32/tests/msg.c
+++ b/dlls/user32/tests/msg.c
@@ -13792,6 +13792,27 @@ static const struct message WmSetLayeredStyle2[] = {
     { 0 }
 };
 
+struct layered_window_info
+{
+    HWND   hwnd;
+    HDC    hdc;
+    SIZE   size;
+    HANDLE event;
+    BOOL   ret;
+};
+
+static DWORD CALLBACK update_layered_proc( void *param )
+{
+    struct layered_window_info *info = param;
+    POINT src = { 0, 0 };
+
+    info->ret = pUpdateLayeredWindow( info->hwnd, 0, NULL, &info->size,
+                                      info->hdc, &src, 0, NULL, ULW_OPAQUE );
+    ok( info->ret, "failed\n");
+    SetEvent( info->event );
+    return 0;
+}
+
 static void test_layered_window(void)
 {
     HWND hwnd;
@@ -13801,6 +13822,9 @@ static void test_layered_window(void)
     SIZE size;
     POINT pos, src;
     RECT rect, client;
+    HANDLE thread;
+    DWORD tid;
+    struct layered_window_info info;
 
     if (!pUpdateLayeredWindow)
     {
@@ -13894,6 +13918,26 @@ static void test_layered_window(void)
         broken(rect.right == client.right - 100 && rect.bottom == client.bottom - 50),
         "wrong client rect %d,%d,%d,%d\n", rect.left, rect.top, rect.right, rect.bottom );
 
+    SetWindowLong( hwnd, GWL_EXSTYLE, GetWindowLong(hwnd, GWL_EXSTYLE) | WS_EX_LAYERED );
+    info.hwnd = hwnd;
+    info.hdc = hdc;
+    info.size.cx = 250;
+    info.size.cy = 300;
+    info.event = CreateEventA( NULL, TRUE, FALSE, NULL );
+    info.ret = FALSE;
+    thread = CreateThread( NULL, 0, update_layered_proc, &info, 0, &tid );
+    ok( WaitForSingleObject( info.event, 1000 ) == 0, "wait failed\n" );
+    ok( info.ret, "UpdateLayeredWindow failed in other thread\n" );
+    WaitForSingleObject( thread, 1000 );
+    CloseHandle( thread );
+    GetWindowRect( hwnd, &rect );
+    ok( rect.left == 200 && rect.top == 200 && rect.right == 450 && rect.bottom == 500,
+        "wrong window rect %d,%d,%d,%d\n", rect.left, rect.top, rect.right, rect.bottom );
+    GetClientRect( hwnd, &rect );
+    ok( (rect.right == 250 && rect.bottom == 300) ||
+        broken(rect.right == client.right - 100 && rect.bottom == client.bottom - 50),
+        "wrong client rect %d,%d,%d,%d\n", rect.left, rect.top, rect.right, rect.bottom );
+
     DestroyWindow( hwnd );
     DeleteDC( hdc );
     DeleteObject( bmp );