diff --git a/src/server.c b/src/server.c
index 19e63b1..6f7c3d6 100644
--- a/src/server.c
+++ b/src/server.c
@@ -4324,7 +4324,7 @@
 	char *be_name, *sv_name;
 	char *errmsg = NULL;
 	int errcode, argc;
-	int i;
+	int next_id, i;
 	const int parse_flags = SRV_PARSE_DYNAMIC|SRV_PARSE_PARSE_ADDR;
 
 	if (!cli_has_level(appctx, ACCESS_LVL_ADMIN))
@@ -4457,6 +4457,24 @@
 		be->srv = srv;
 	}
 
+	/* generate the server id if not manually specified */
+	if (!srv->puid) {
+		next_id = get_next_id(&be->conf.used_server_id, 1);
+		if (!next_id) {
+			ha_alert("Cannot attach server : no id left in proxy\n");
+			goto out;
+		}
+
+		srv->conf.id.key = srv->puid = next_id;
+		srv->conf.name.key = srv->id;
+	}
+
+	/* insert the server in the backend trees */
+	if (!(srv->flags & SRV_F_FORCED_ID)) {
+		eb32_insert(&be->conf.used_server_id, &srv->conf.id);
+		ebis_insert(&be->conf.used_server_name, &srv->conf.name);
+	}
+
 	thread_release();
 
 	ha_notice("New server %s/%s registered.\n", be->id, srv->id);