diff --git a/include/proto/stream_interface.h b/include/proto/stream_interface.h
index 4dfd20f..aba94c7 100644
--- a/include/proto/stream_interface.h
+++ b/include/proto/stream_interface.h
@@ -108,7 +108,7 @@
 	si->err_type       = SI_ET_NONE;
 	si->conn_retries   = 0;  /* used for logging too */
 	si->exp            = TICK_ETERNITY;
-	si->flags          = SI_FL_NONE;
+	si->flags         &= SI_FL_ISBACK;
 	si->end            = NULL;
 	si->state          = si->prev_state = SI_ST_INI;
 }