diff --git a/clutter/clutter-actor.c b/clutter/clutter-actor.c
index 7706cf6cf..944c0a465 100644
--- a/clutter/clutter-actor.c
+++ b/clutter/clutter-actor.c
@@ -1724,9 +1724,9 @@ clutter_actor_real_allocate (ClutterActor           *self,
   ClutterActorPrivate *priv = self->priv;
   gboolean x1_changed, y1_changed, x2_changed, y2_changed;
   gboolean flags_changed;
-  ClutterActorBox old = { 0, };
+  ClutterActorBox old_alloc = { 0, };
 
-  clutter_actor_store_old_geometry (self, &old);
+  clutter_actor_store_old_geometry (self, &old_alloc);
 
   x1_changed = priv->allocation.x1 != box->x1;
   y1_changed = priv->allocation.y1 != box->y1;
@@ -1749,11 +1749,11 @@ clutter_actor_real_allocate (ClutterActor           *self,
        * that wish to track the allocation flags
        */
       g_signal_emit (self, actor_signals[ALLOCATION_CHANGED], 0,
-                     box,
+                     &priv->allocation,
                      flags);
     }
 
-  clutter_actor_notify_if_geometry_changed (self, &old);
+  clutter_actor_notify_if_geometry_changed (self, &old_alloc);
 
   g_object_thaw_notify (G_OBJECT (self));
 }
@@ -4059,7 +4059,7 @@ clutter_actor_class_init (ClutterActorClass *klass)
   /**
    * ClutterActor:constraints:
    *
-   * Adds a #ClutterConstaint to the actor
+   * Adds a #ClutterConstraint to the actor
    *
    * Since: 1.4
    */
@@ -5279,6 +5279,7 @@ clutter_actor_allocate (ClutterActor           *self,
 {
   ClutterActorPrivate *priv;
   ClutterActorClass *klass;
+  ClutterActorBox alloc;
   gboolean child_moved;
 
   g_return_if_fail (CLUTTER_IS_ACTOR (self));
@@ -5292,8 +5293,22 @@ clutter_actor_allocate (ClutterActor           *self,
 
   priv = self->priv;
 
-  child_moved = (box->x1 != priv->allocation.x1 ||
-                 box->y1 != priv->allocation.y1);
+  alloc = *box;
+
+  if (priv->constraints != NULL)
+    {
+      const GList *constraints, *l;
+
+      constraints = _clutter_meta_group_peek_metas (priv->constraints);
+      for (l = constraints; l != NULL; l = l->next)
+        {
+          ClutterConstraint *constraint = l->data;
+          _clutter_constraint_update_allocation (constraint, self, &alloc);
+        }
+    }
+
+  child_moved = (alloc.x1 != priv->allocation.x1 ||
+                 alloc.y1 != priv->allocation.y1);
 
   /* If we get an allocation "out of the blue"
    * (we did not queue relayout), then we want to
@@ -5311,8 +5326,8 @@ clutter_actor_allocate (ClutterActor           *self,
   if (!priv->needs_allocation &&
       !(flags & CLUTTER_ABSOLUTE_ORIGIN_CHANGED) &&
       !child_moved &&
-      box->x2 == priv->allocation.x2 &&
-      box->y2 == priv->allocation.y2)
+      alloc.x2 == priv->allocation.x2 &&
+      alloc.y2 == priv->allocation.y2)
     {
       CLUTTER_NOTE (LAYOUT, "No allocation needed");
       return;
@@ -5330,7 +5345,7 @@ clutter_actor_allocate (ClutterActor           *self,
   CLUTTER_SET_PRIVATE_FLAGS (self, CLUTTER_IN_RELAYOUT);
 
   klass = CLUTTER_ACTOR_GET_CLASS (self);
-  klass->allocate (self, box, flags);
+  klass->allocate (self, &alloc, flags);
 
   CLUTTER_UNSET_PRIVATE_FLAGS (self, CLUTTER_IN_RELAYOUT);
 }
diff --git a/clutter/clutter-constraint.c b/clutter/clutter-constraint.c
index 46f86f7b0..6e0bf2865 100644
--- a/clutter/clutter-constraint.c
+++ b/clutter/clutter-constraint.c
@@ -8,8 +8,10 @@
  * position or size.
  *
  * A #ClutterConstraint sub-class should contain the logic for modifying
- * the position or size of the #ClutterActor to which it is applied, using
- * the various signals and properties of #ClutterActor itself.
+ * the position or size of the #ClutterActor to which it is applied, by
+ * updating the actor's allocation. Each #ClutterConstraint can change the
+ * allocation of the actor to which they are applied by overriding the
+ * <function>update_allocation()</function> virtual function.
  *
  * #ClutterConstraint is available since Clutter 1.4
  */
@@ -20,18 +22,41 @@
 
 #include "clutter-constraint.h"
 
+#include "clutter-actor.h"
 #include "clutter-actor-meta-private.h"
 
 G_DEFINE_ABSTRACT_TYPE (ClutterConstraint,
                         clutter_constraint,
                         CLUTTER_TYPE_ACTOR_META);
 
+static void
+constraint_update_allocation (ClutterConstraint *constraint,
+                              ClutterActor      *actor,
+                              ClutterActorBox   *allocation)
+{
+}
+
 static void
 clutter_constraint_class_init (ClutterConstraintClass *klass)
 {
+  klass->update_allocation = constraint_update_allocation;
 }
 
 static void
 clutter_constraint_init (ClutterConstraint *self)
 {
 }
+
+void
+_clutter_constraint_update_allocation (ClutterConstraint *constraint,
+                                       ClutterActor      *actor,
+                                       ClutterActorBox   *allocation)
+{
+  g_return_if_fail (CLUTTER_IS_CONSTRAINT (constraint));
+  g_return_if_fail (CLUTTER_IS_ACTOR (actor));
+  g_return_if_fail (allocation != NULL);
+
+  CLUTTER_CONSTRAINT_GET_CLASS (constraint)->update_allocation (constraint,
+                                                                actor,
+                                                                allocation);
+}
diff --git a/clutter/clutter-constraint.h b/clutter/clutter-constraint.h
index 948670585..6d2eabdc7 100644
--- a/clutter/clutter-constraint.h
+++ b/clutter/clutter-constraint.h
@@ -69,6 +69,10 @@ struct _ClutterConstraintClass
   /*< private >*/
   ClutterActorMetaClass parent_class;
 
+  void (* update_allocation) (ClutterConstraint *constraint,
+                              ClutterActor      *actor,
+                              ClutterActorBox   *allocation);
+
   /*< private >*/
   void (* _clutter_constraint1) (void);
   void (* _clutter_constraint2) (void);
diff --git a/clutter/clutter-private.h b/clutter/clutter-private.h
index 1c27aea7c..7c460d393 100644
--- a/clutter/clutter-private.h
+++ b/clutter/clutter-private.h
@@ -383,6 +383,10 @@ gint32 _clutter_backend_get_units_serial (ClutterBackend *backend);
 gboolean _clutter_effect_pre_paint  (ClutterEffect *effect);
 void     _clutter_effect_post_paint (ClutterEffect *effect);
 
+void _clutter_constraint_update_allocation (ClutterConstraint *constraint,
+                                            ClutterActor      *actor,
+                                            ClutterActorBox   *allocation);
+
 GType _clutter_layout_manager_get_child_meta_type (ClutterLayoutManager *manager);
 
 void     _clutter_event_set_platform_data (ClutterEvent       *event,