diff --git a/README.in b/README.in
index 8511064179..c002e115eb 100644
--- a/README.in
+++ b/README.in
@@ -81,6 +81,13 @@ Release notes for 3.10
   setups (not multi-monitor!) are very rare nowadays. If you really
   need multiple X screens, open them as separate displays.
 
+* The behavior of GtkBox::expand has been changed to never propagate
+  up. Previously, this was happening inconsistently. If you want the
+  expand to propagate, use the GtkWidget h/v expand properties.
+  If you experience sizing problems with widgets in ported code,
+  carefully check the expand and fill flags of your boxes.
+
+
 Release notes for 3.8
 =====================
 
diff --git a/gtk/gtkbox.c b/gtk/gtkbox.c
index e60fb4fa90..94e89073cc 100644
--- a/gtk/gtkbox.c
+++ b/gtk/gtkbox.c
@@ -150,9 +150,6 @@ struct _GtkBoxChild
 static void gtk_box_size_allocate         (GtkWidget              *widget,
                                            GtkAllocation          *allocation);
 
-static void gtk_box_compute_expand     (GtkWidget      *widget,
-                                        gboolean       *hexpand,
-                                        gboolean       *vexpand);
 static void gtk_box_direction_changed  (GtkWidget        *widget,
                                         GtkTextDirection  previous_direction);
 
@@ -230,7 +227,6 @@ gtk_box_class_init (GtkBoxClass *class)
   widget_class->get_preferred_height_for_width = gtk_box_get_preferred_height_for_width;
   widget_class->get_preferred_height_and_baseline_for_width = gtk_box_get_preferred_height_and_baseline_for_width;
   widget_class->get_preferred_width_for_height = gtk_box_get_preferred_width_for_height;
-  widget_class->compute_expand                 = gtk_box_compute_expand;
   widget_class->direction_changed              = gtk_box_direction_changed;
 
   container_class->add = gtk_box_add;
@@ -285,6 +281,9 @@ gtk_box_class_init (GtkBoxClass *class)
    * Note that the #GtkWidget:halign, #GtkWidget:valign, #GtkWidget:hexpand
    * and #GtkWidget:vexpand properties are the preferred way to influence
    * child size allocation in containers.
+   *
+   * In contrast to #GtkWidget::hexpand, the expand child property does
+   * not cause the box to expand itself.
    */
   gtk_container_class_install_child_property (container_class,
 					      CHILD_PROP_EXPAND,
@@ -779,53 +778,6 @@ gtk_box_size_allocate (GtkWidget     *widget,
     }
 }
 
-static void
-gtk_box_compute_expand (GtkWidget      *widget,
-                        gboolean       *hexpand_p,
-                        gboolean       *vexpand_p)
-{
-  GtkBoxPrivate  *private = GTK_BOX (widget)->priv;
-  GList       *children;
-  GtkBoxChild *child;
-  gboolean our_expand;
-  gboolean opposite_expand;
-  GtkOrientation opposite_orientation;
-
-  opposite_orientation = OPPOSITE_ORIENTATION (private->orientation);
-
-  our_expand = FALSE;
-  opposite_expand = FALSE;
-
-  for (children = private->children; children; children = children->next)
-    {
-      child = children->data;
-
-      /* we don't recurse into children anymore as soon as we know
-       * expand=TRUE in an orientation
-       */
-
-      if (child->expand || (!our_expand && gtk_widget_compute_expand (child->widget, private->orientation)))
-        our_expand = TRUE;
-
-      if (!opposite_expand && gtk_widget_compute_expand (child->widget, opposite_orientation))
-        opposite_expand = TRUE;
-
-      if (our_expand && opposite_expand)
-        break;
-    }
-
-  if (private->orientation == GTK_ORIENTATION_HORIZONTAL)
-    {
-      *hexpand_p = our_expand;
-      *vexpand_p = opposite_expand;
-    }
-  else
-    {
-      *hexpand_p = opposite_expand;
-      *vexpand_p = our_expand;
-    }
-}
-
 static GType
 gtk_box_child_type (GtkContainer   *container)
 {