diff --git a/gst/isomp4/gstqtmux.c b/gst/isomp4/gstqtmux.c
index c43d612ce2..a8fc7cdab5 100644
--- a/gst/isomp4/gstqtmux.c
+++ b/gst/isomp4/gstqtmux.c
@@ -1414,6 +1414,7 @@ gst_qt_mux_add_metadata_tags (GstQTMux * qtmux, const GstTagList * list,
         }
         gst_buffer_unmap (buf, &map);
       }
+      gst_sample_unref (sample);
     }
   }