diff --git a/gst-libs/gst/codecs/gsth264decoder.c b/gst-libs/gst/codecs/gsth264decoder.c
index 1ee6f54de1..554ab1e03a 100644
--- a/gst-libs/gst/codecs/gsth264decoder.c
+++ b/gst-libs/gst/codecs/gsth264decoder.c
@@ -1525,6 +1525,8 @@ gst_h264_decoder_drain_output_queue (GstH264Decoder * self, guint num)
   GstH264DecoderPrivate *priv = self->priv;
   GstH264DecoderClass *klass = GST_H264_DECODER_GET_CLASS (self);
 
+  g_assert (klass->output_picture);
+
   while (gst_queue_array_get_length (priv->output_queue) > num) {
     GstH264DecoderOutputFrame *output_frame = (GstH264DecoderOutputFrame *)
         gst_queue_array_pop_head_struct (priv->output_queue);