diff --git a/lib/iscsi/conn.c b/lib/iscsi/conn.c
index 37c49a33b..fd198785d 100644
--- a/lib/iscsi/conn.c
+++ b/lib/iscsi/conn.c
@@ -188,6 +188,7 @@ iscsi_poll_group_remove_conn(struct spdk_iscsi_poll_group *pg, struct spdk_iscsi
 {
 	int rc;
 
+	assert(conn->sock != NULL);
 	rc = spdk_sock_group_remove_sock(pg->sock_group, conn->sock);
 	if (rc < 0) {
 		SPDK_ERRLOG("Failed to remove sock=%p of conn=%p\n", conn->sock, conn);