diff --git a/util.c b/util.c
index 3ab12368..e3c435b5 100644
--- a/util.c
+++ b/util.c
@@ -1482,7 +1482,7 @@ bool initiate_stratum(struct pool *pool)
 	if (pool->sessionid)
 		applog(LOG_DEBUG, "Pool %d stratum session id: %s", pool->pool_no, pool->sessionid);
 	else
-		applog(LOG_DEBUG, "Pool %d stratum session id does not exist");
+		applog(LOG_DEBUG, "Pool %d stratum session id does not exist", pool->pool_no);
 
 	ret = true;
 out: