diff --git a/gtk/gtkglarea.c b/gtk/gtkglarea.c
index d0882b7e36..3b030f50dd 100644
--- a/gtk/gtkglarea.c
+++ b/gtk/gtkglarea.c
@@ -268,6 +268,8 @@ gtk_gl_area_realize (GtkWidget *widget)
 
   GTK_WIDGET_CLASS (gtk_gl_area_parent_class)->realize (widget);
 
+  gtk_widget_get_allocation (widget, &allocation);
+
   attributes.window_type = GDK_WINDOW_CHILD;
   attributes.x = allocation.x;
   attributes.y = allocation.y;