diff --git a/src/core/constraints.c b/src/core/constraints.c
index b59aa065f..c6950ce01 100644
--- a/src/core/constraints.c
+++ b/src/core/constraints.c
@@ -426,7 +426,7 @@ setup_constraint_info (ConstraintInfo      *info,
    */
   if (meta_prefs_get_force_fullscreen() &&
       !window->hide_titlebar_when_maximized &&
-      window->decorated &&
+      (window->decorated || !meta_window_is_client_decorated (window)) &&
       meta_rectangle_equal (new, &monitor_info->rect) &&
       window->has_fullscreen_func &&
       !window->fullscreen)
diff --git a/src/core/window-private.h b/src/core/window-private.h
index b282efe36..03f671525 100644
--- a/src/core/window-private.h
+++ b/src/core/window-private.h
@@ -694,4 +694,6 @@ Window meta_window_get_toplevel_xwindow (MetaWindow *window);
 void meta_window_get_client_area_rect (const MetaWindow      *window,
                                        cairo_rectangle_int_t *rect);
 
+gboolean meta_window_is_client_decorated (MetaWindow *window);
+
 #endif
diff --git a/src/core/window.c b/src/core/window.c
index 2593f2769..2ac5a10c9 100644
--- a/src/core/window.c
+++ b/src/core/window.c
@@ -10127,6 +10127,24 @@ meta_window_same_client (MetaWindow *window,
           (other_window->xwindow & ~resource_mask));
 }
 
+/**
+ * meta_window_is_client_decorated:
+ *
+ * Check if if the window has decorations drawn by the client.
+ * (window->decorated refers only to whether we should add decorations)
+ */
+gboolean
+meta_window_is_client_decorated (MetaWindow *window)
+{
+  /* Currently the implementation here is hackish -
+   * has_custom_frame_extents() is set if _GTK_FRAME_EXTENTS is set
+   * to any value even 0. GTK+ always sets _GTK_FRAME_EXTENTS for
+   * client-side-decorated window, even if the value is 0 because
+   * the window is maxized and has no invisible borders or shadows.
+   */
+  return window->has_custom_frame_extents;
+}
+
 void
 meta_window_refresh_resize_popup (MetaWindow *window)
 {