diff --git a/gtk/gtkcsscomputedvalues.c b/gtk/gtkcsscomputedvalues.c
index 608575e38c..ac2718f44a 100644
--- a/gtk/gtkcsscomputedvalues.c
+++ b/gtk/gtkcsscomputedvalues.c
@@ -227,3 +227,25 @@ _gtk_css_computed_values_get_section (GtkCssComputedValues *values,
   return g_ptr_array_index (values->sections, id);
 }
 
+GtkBitmask *
+_gtk_css_computed_values_get_difference (GtkCssComputedValues *values,
+                                         GtkCssComputedValues *other)
+{
+  GtkBitmask *result;
+  guint i, len;
+
+  len = MIN (values->values->len, other->values->len);
+  result = _gtk_bitmask_new ();
+  if (values->values->len != other->values->len)
+    result = _gtk_bitmask_invert_range (result, len, MAX (values->values->len, other->values->len));
+  
+  for (i = 0; i < len; i++)
+    {
+      if (!_gtk_css_value_equal (g_ptr_array_index (values->values, i),
+                                 g_ptr_array_index (other->values, i)))
+        result = _gtk_bitmask_set (result, i, TRUE);
+    }
+
+  return result;
+}
+
diff --git a/gtk/gtkcsscomputedvaluesprivate.h b/gtk/gtkcsscomputedvaluesprivate.h
index 81c9cf2519..64234ef371 100644
--- a/gtk/gtkcsscomputedvaluesprivate.h
+++ b/gtk/gtkcsscomputedvaluesprivate.h
@@ -22,6 +22,7 @@
 
 #include <glib-object.h>
 
+#include "gtk/gtkbitmaskprivate.h"
 #include "gtk/gtkcsssection.h"
 #include "gtk/gtkstylecontext.h"
 #include "gtk/gtkcssvalueprivate.h"
@@ -69,6 +70,8 @@ GtkCssValue *           _gtk_css_computed_values_get_value            (GtkCssCom
                                                                        guint                     id);
 GtkCssSection *         _gtk_css_computed_values_get_section          (GtkCssComputedValues     *values,
                                                                        guint                     id);
+GtkBitmask *            _gtk_css_computed_values_get_difference       (GtkCssComputedValues     *values,
+                                                                       GtkCssComputedValues     *other);
 
 
 G_END_DECLS
diff --git a/gtk/gtkstylecontext.c b/gtk/gtkstylecontext.c
index 103f235df4..b50f9d0602 100644
--- a/gtk/gtkstylecontext.c
+++ b/gtk/gtkstylecontext.c
@@ -2830,12 +2830,31 @@ _gtk_style_context_validate (GtkStyleContext *context,
   if (priv->relevant_changes & change)
     {
       GtkStyleInfo *info = priv->info_stack->data;
+      GtkCssComputedValues *old, *new;
+
+      old = info->data ? g_object_ref (info->data->store) : NULL;
 
       if ((priv->relevant_changes & change) & ~GTK_STYLE_CONTEXT_CACHED_CHANGE)
         gtk_style_context_clear_cache (context);
+      else
+        info->data = NULL;
+
+      if (old)
+        {
+          GtkBitmask *bitmask;
+
+          new = style_data_lookup (context)->store;
+
+          bitmask = _gtk_css_computed_values_get_difference (new, old);
+          if (!_gtk_bitmask_is_empty (bitmask))
+            gtk_style_context_do_invalidate (context);
+
+          _gtk_bitmask_free (bitmask);
+          g_object_unref (old);
+        }
+      else
+        gtk_style_context_do_invalidate (context);
 
-      info->data = NULL;
-      gtk_style_context_do_invalidate (context);
     }
 
   change = _gtk_css_change_for_child (change);