diff --git a/gtk/gtkcontainer.c b/gtk/gtkcontainer.c
index 731fad2c75..d681dbde65 100644
--- a/gtk/gtkcontainer.c
+++ b/gtk/gtkcontainer.c
@@ -1846,16 +1846,10 @@ gtk_container_idle_sizer (GdkFrameClock *clock,
    */
   if (container->priv->restyle_pending)
     {
-      GtkBitmask *empty;
-
-      empty = _gtk_bitmask_new ();
-
       container->priv->restyle_pending = FALSE;
       gtk_css_node_validate (gtk_widget_get_css_node (GTK_WIDGET (container)),
                              gdk_frame_clock_get_frame_time (gtk_widget_get_frame_clock (GTK_WIDGET (container))),
-                             empty);
-
-      _gtk_bitmask_free (empty);
+                             FALSE);
     }
 
   /* we may be invoked with a container_resize_queue of NULL, because
diff --git a/gtk/gtkcssnode.c b/gtk/gtkcssnode.c
index b9b6bbcb78..d9ea83c49c 100644
--- a/gtk/gtkcssnode.c
+++ b/gtk/gtkcssnode.c
@@ -241,13 +241,13 @@ gtk_css_node_real_dequeue_validate (GtkCssNode *node)
 {
 }
 
-static GtkBitmask *
+static gboolean
 gtk_css_node_real_validate (GtkCssNode       *cssnode,
                             gint64            timestamp,
                             GtkCssChange      change,
-                            const GtkBitmask *parent_changes)
+                            gboolean          parent_changed)
 {
-  return _gtk_bitmask_new ();
+  return FALSE;
 }
 
 gboolean
@@ -703,11 +703,11 @@ gtk_css_node_propagate_pending_changes (GtkCssNode *cssnode)
 void
 gtk_css_node_validate (GtkCssNode            *cssnode,
                        gint64                 timestamp,
-                       const GtkBitmask      *parent_changes)
+                       gboolean               parent_changed)
 {
   GtkCssChange change;
   GtkCssNode *child;
-  GtkBitmask *changes;
+  gboolean changed;
 
   /* If you run your application with
    *   GTK_DEBUG=no-css-cache
@@ -726,7 +726,7 @@ gtk_css_node_validate (GtkCssNode            *cssnode,
 
   gtk_css_node_propagate_pending_changes (cssnode);
 
-  if (!cssnode->invalid && change == 0 && _gtk_bitmask_is_empty (parent_changes))
+  if (!cssnode->invalid && change == 0 && !parent_changed)
     return;
 
   gtk_css_node_set_invalid (cssnode, FALSE);
@@ -734,17 +734,15 @@ gtk_css_node_validate (GtkCssNode            *cssnode,
   change = cssnode->pending_changes;
   cssnode->pending_changes = 0;
 
-  changes = GTK_CSS_NODE_GET_CLASS (cssnode)->validate (cssnode, timestamp, change, parent_changes);
+  changed = GTK_CSS_NODE_GET_CLASS (cssnode)->validate (cssnode, timestamp, change, parent_changed);
 
   for (child = gtk_css_node_get_first_child (cssnode);
        child;
        child = gtk_css_node_get_next_sibling (child))
     {
       if (child->visible)
-        gtk_css_node_validate (child, timestamp, changes);
+        gtk_css_node_validate (child, timestamp, changed);
     }
-
-  _gtk_bitmask_free (changes);
 }
 
 gboolean
diff --git a/gtk/gtkcssnodeprivate.h b/gtk/gtkcssnodeprivate.h
index c9bbe5709e..33949990d4 100644
--- a/gtk/gtkcssnodeprivate.h
+++ b/gtk/gtkcssnodeprivate.h
@@ -69,10 +69,10 @@ struct _GtkCssNodeClass
   void                  (* invalidate)                  (GtkCssNode            *node);
   void                  (* queue_validate)              (GtkCssNode            *node);
   void                  (* dequeue_validate)            (GtkCssNode            *node);
-  GtkBitmask *          (* validate)                    (GtkCssNode            *cssnode,
+  gboolean              (* validate)                    (GtkCssNode            *cssnode,
                                                          gint64                 timestamp,
                                                          GtkCssChange           change,
-                                                         const GtkBitmask      *parent_changes);
+                                                         gboolean               parent_changed);
 };
 
 GType                   gtk_css_node_get_type           (void) G_GNUC_CONST;
@@ -135,7 +135,7 @@ void                    gtk_css_node_invalidate         (GtkCssNode            *
                                                          GtkCssChange           change);
 void                    gtk_css_node_validate           (GtkCssNode            *cssnode,
                                                          gint64                 timestamp,
-                                                         const GtkBitmask      *parent_changes);
+                                                         gboolean               parent_changed);
 void                    gtk_css_node_set_invalid        (GtkCssNode            *node,
                                                          gboolean               invalid);
 
diff --git a/gtk/gtkcsswidgetnode.c b/gtk/gtkcsswidgetnode.c
index 9a662df9b3..ca4828454d 100644
--- a/gtk/gtkcsswidgetnode.c
+++ b/gtk/gtkcsswidgetnode.c
@@ -88,10 +88,10 @@ static GtkCssStyle *
 validate_static_style (GtkCssNode       *node,
                        GtkCssStyle      *style,
                        GtkCssChange      change,
-                       const GtkBitmask *parent_changes)
+                       gboolean          parent_changed)
 {
   if (gtk_css_static_style_needs_revalidate (GTK_CSS_STATIC_STYLE (style), change) ||
-      !_gtk_bitmask_is_empty (parent_changes))
+      parent_changed)
     {
       return gtk_css_node_create_style (node);
     }
@@ -101,20 +101,21 @@ validate_static_style (GtkCssNode       *node,
     }
 }
 
-static GtkBitmask *
+static gboolean
 gtk_css_widget_node_validate (GtkCssNode       *node,
                               gint64            timestamp,
                               GtkCssChange      change,
-                              const GtkBitmask *parent_changes)
+                              gboolean          parent_changed)
 {
   GtkCssWidgetNode *widget_node = GTK_CSS_WIDGET_NODE (node);
   GtkStyleContext *context;
   GtkBitmask *changes;
   GtkCssStyle *style, *static_style;
   GtkCssStyle *new_style, *new_static_style;
+  gboolean result;
 
   if (widget_node->widget == NULL)
-    return _gtk_bitmask_new ();
+    return FALSE;
 
   context = gtk_widget_get_style_context (widget_node->widget);
   style = gtk_css_node_get_style (node);
@@ -130,7 +131,7 @@ gtk_css_widget_node_validate (GtkCssNode       *node,
       static_style = style;
     }
 
-  new_static_style = validate_static_style (node, static_style, change, parent_changes);
+  new_static_style = validate_static_style (node, static_style, change, parent_changed);
 
   if (new_static_style != static_style)
     {
@@ -165,7 +166,10 @@ gtk_css_widget_node_validate (GtkCssNode       *node,
 
   gtk_style_context_validate (context, changes);
 
-  return changes;
+  result = !_gtk_bitmask_is_empty (changes);
+  _gtk_bitmask_free (changes);
+
+  return result;
 }
 
 typedef GtkWidgetPath * (* GetPathForChildFunc) (GtkContainer *, GtkWidget *);
diff --git a/gtk/gtkwindow.c b/gtk/gtkwindow.c
index 0a5202009f..9a611cbfe6 100644
--- a/gtk/gtkwindow.c
+++ b/gtk/gtkwindow.c
@@ -5834,7 +5834,6 @@ gtk_window_show (GtkWidget *widget)
   GtkWindow *window = GTK_WINDOW (widget);
   GtkWindowPrivate *priv = window->priv;
   GtkContainer *container = GTK_CONTAINER (window);
-  GtkBitmask *empty;
   gboolean need_resize;
   gboolean is_plug;
 
@@ -5848,11 +5847,9 @@ gtk_window_show (GtkWidget *widget)
 
   need_resize = _gtk_widget_get_alloc_needed (widget) || !gtk_widget_get_realized (widget);
 
-  empty = _gtk_bitmask_new ();
   gtk_css_node_validate (gtk_widget_get_css_node (widget),
                          g_get_monotonic_time (),
-                         empty);
-  _gtk_bitmask_free (empty);
+                         FALSE);
 
   if (need_resize)
     {