diff --git a/doc/configuration.txt b/doc/configuration.txt
index 0d6ba70d1..65dafcb5d 100644
--- a/doc/configuration.txt
+++ b/doc/configuration.txt
@@ -18876,9 +18876,13 @@ healthcheck <name>
 id <value>
   May be used in the following contexts: tcp, http, log
 
-  Set a persistent ID for the server. This ID must be positive and unique for
-  the proxy. An unused ID will automatically be assigned if unset. The first
-  assigned value will be 1. This ID is currently only returned in statistics.
+  Set a persistent ID for the server. This ID must be a 32-bit positive number
+  and unique for the proxy. An unused ID will automatically be assigned if
+  unset. The first assigned value will be 1. This ID is currently only returned
+  in statistics, and is used to place LB nodes when using consistent hash
+  algorithms when "hash-key" is set to "id" (the default). In this case, only
+  the 28 lowest bits of the value are used (i.e. (id % 268435356)), so better
+  only use values comprised between 1 and this value to avoid overlap.
 
 idle-ping <delay>
   May be used in the following contexts: tcp, http, log
diff --git a/src/server.c b/src/server.c
index 9d6a2f481..819e1c05a 100644
--- a/src/server.c
+++ b/src/server.c
@@ -1313,19 +1313,20 @@ static int srv_parse_pool_max_conn(char **args, int *cur_arg, struct proxy *curp
 static int srv_parse_id(char **args, int *cur_arg, struct proxy *curproxy, struct server *newsrv, char **err)
 {
 	struct server *target;
+	llong id;
 
 	if (!*args[*cur_arg + 1]) {
 		memprintf(err, "'%s' : expects an integer argument", args[*cur_arg]);
 		return ERR_ALERT | ERR_FATAL;
 	}
 
-	newsrv->puid = atol(args[*cur_arg + 1]);
-
-	if (newsrv->puid <= 0) {
-		memprintf(err, "'%s' : custom id has to be > 0", args[*cur_arg]);
+	id = atol(args[*cur_arg + 1]);
+	if (id < 1 || id > ~0U) {
+		memprintf(err, "'%s' : custom id has to be between 1 and 4294967295.", args[*cur_arg]);
 		return ERR_ALERT | ERR_FATAL;
 	}
 
+	newsrv->puid = id;
 	target = server_find_by_id(curproxy, newsrv->puid);
 	if (target) {
 		memprintf(err, "'%s' : custom id %d already used at %s:%d ('server %s')",