diff --git a/gst-libs/gst/gl/gstglwindow.c b/gst-libs/gst/gl/gstglwindow.c
index 2e1775c788..bc00b170a3 100644
--- a/gst-libs/gst/gl/gstglwindow.c
+++ b/gst-libs/gst/gl/gstglwindow.c
@@ -183,6 +183,8 @@ gst_gl_window_finalize (GObject * object)
 
   g_weak_ref_clear (&window->context_ref);
 
+  g_mutex_clear (&window->lock);
+
   G_OBJECT_CLASS (gst_gl_window_parent_class)->finalize (object);
 }