diff --git a/gtk/gtkcssanimatedstyle.c b/gtk/gtkcssanimatedstyle.c
index 82cf1acbe9..1ea4918101 100644
--- a/gtk/gtkcssanimatedstyle.c
+++ b/gtk/gtkcssanimatedstyle.c
@@ -645,15 +645,20 @@ gtk_css_animated_style_get_intrinsic_value (GtkCssAnimatedStyle *style,
   return gtk_css_style_get_value (style->style, id);
 }
 
-void
+gboolean
 gtk_css_animated_style_set_animated_custom_value (GtkCssAnimatedStyle *animated,
                                                   int                  id,
                                                   GtkCssVariableValue *value)
 {
   GtkCssStyle *style = (GtkCssStyle *)animated;
+  GtkCssVariableValue *old_value;
 
-  gtk_internal_return_if_fail (GTK_IS_CSS_ANIMATED_STYLE (style));
-  gtk_internal_return_if_fail (value != NULL);
+  gtk_internal_return_val_if_fail (GTK_IS_CSS_ANIMATED_STYLE (style), FALSE);
+  gtk_internal_return_val_if_fail (value != NULL, FALSE);
+
+  old_value = gtk_css_style_get_custom_property (style, id);
+  if (gtk_css_value_equal0 ((GtkCssValue *) old_value, (GtkCssValue *) value))
+    return FALSE;
 
   if (style->variables == NULL)
     {
@@ -669,6 +674,8 @@ gtk_css_animated_style_set_animated_custom_value (GtkCssAnimatedStyle *animated,
     }
 
   gtk_css_variable_set_add (style->variables, id, value);
+
+  return TRUE;
 }
 
 void
diff --git a/gtk/gtkcssanimatedstyleprivate.h b/gtk/gtkcssanimatedstyleprivate.h
index ada5ad75f8..2c8420e7bc 100644
--- a/gtk/gtkcssanimatedstyleprivate.h
+++ b/gtk/gtkcssanimatedstyleprivate.h
@@ -70,7 +70,7 @@ void                    gtk_css_animated_style_set_animated_value(GtkCssAnimated
 GtkCssValue *           gtk_css_animated_style_get_intrinsic_value (GtkCssAnimatedStyle *style,
                                                                  guint                   id);
 
-void                    gtk_css_animated_style_set_animated_custom_value (GtkCssAnimatedStyle *animated,
+gboolean                gtk_css_animated_style_set_animated_custom_value (GtkCssAnimatedStyle *animated,
                                                                  int                     id,
                                                                  GtkCssVariableValue    *value);
 
diff --git a/gtk/gtkcssanimation.c b/gtk/gtkcssanimation.c
index d920d4d71a..7c09a370b0 100644
--- a/gtk/gtkcssanimation.c
+++ b/gtk/gtkcssanimation.c
@@ -126,11 +126,10 @@ gtk_css_animation_apply_values (GtkStyleAnimation    *style_animation,
       if (!value)
         continue;
 
-      gtk_css_animated_style_set_animated_custom_value (style, variable_id, value);
+      if (gtk_css_animated_style_set_animated_custom_value (style, variable_id, value))
+        change |= GTK_CSS_ANIMATION_CHANGE_VARIABLES;
 
       gtk_css_variable_value_unref (value);
-
-      change |= GTK_CSS_ANIMATION_CHANGE_VARIABLES;
     }
 
   for (i = 0; i < _gtk_css_keyframes_get_n_properties (resolved_keyframes); i++)