diff --git a/src/or/relay.c b/src/or/relay.c
index a6a8fef7071a47c04d010f842364f0de6823c887..b4592e85f8758f210f0a2520533d8ca5b226a639 100644
--- a/src/or/relay.c
+++ b/src/or/relay.c
@@ -1048,7 +1048,8 @@ connection_edge_process_relay_cell(cell_t *cell, circuit_t *circ,
       circuit_consider_sending_sendme(circ, layer_hint);
 
       if (!conn) {
-        log_info(domain,"data cell dropped, unknown stream.");
+        log_info(domain,"data cell dropped, unknown stream (streamid %d).",
+                 rh.stream_id);
         return 0;
       }