diff --git a/gst/rtp/gstrtph265depay.c b/gst/rtp/gstrtph265depay.c
index dca0add..ce62777 100644
--- a/gst/rtp/gstrtph265depay.c
+++ b/gst/rtp/gstrtph265depay.c
@@ -1237,6 +1237,7 @@
           if (rtph265depay->byte_stream) {
             memcpy (map.data, sync_bytes, sizeof (sync_bytes));
           } else {
+            gst_buffer_unmap (outbuf, &map);
             goto not_implemented;
           }
 
@@ -1402,6 +1403,7 @@
         if (rtph265depay->byte_stream) {
           memcpy (map.data, sync_bytes, sizeof (sync_bytes));
         } else {
+          gst_buffer_unmap (outbuf, &map);
           goto not_implemented;
         }
         memcpy (map.data + sizeof (sync_bytes), payload, nalu_size);