diff --git a/ext/gtk/gtkgstglwidget.c b/ext/gtk/gtkgstglwidget.c
index 81950342d5..2e108c9f93 100644
--- a/ext/gtk/gtkgstglwidget.c
+++ b/ext/gtk/gtkgstglwidget.c
@@ -586,7 +586,7 @@ gtk_gst_gl_widget_set_buffer (GtkGstGLWidget * widget, GstBuffer * buffer)
   GMainContext *main_context = g_main_context_default ();
 
   g_return_if_fail (GTK_IS_GST_GL_WIDGET (widget));
-  g_return_if_fail (widget->priv->negotiated);
+  g_return_if_fail (buffer == NULL || widget->priv->negotiated);
 
   g_mutex_lock (&widget->priv->lock);
 
diff --git a/ext/gtk/gtkgstwidget.c b/ext/gtk/gtkgstwidget.c
index 36a787423f..e232eebe88 100644
--- a/ext/gtk/gtkgstwidget.c
+++ b/ext/gtk/gtkgstwidget.c
@@ -341,7 +341,7 @@ gtk_gst_widget_set_buffer (GtkGstWidget * widget, GstBuffer * buffer)
   GMainContext *main_context = g_main_context_default ();
 
   g_return_if_fail (GTK_IS_GST_WIDGET (widget));
-  g_return_if_fail (widget->priv->negotiated);
+  g_return_if_fail (buffer == NULL || widget->priv->negotiated);
 
   g_mutex_lock (&widget->priv->lock);