diff --git a/include/proto/backend.h b/include/proto/backend.h
index b4dfc83..24cd909 100644
--- a/include/proto/backend.h
+++ b/include/proto/backend.h
@@ -35,8 +35,7 @@
 int connect_server(struct session *s);
 int srv_redispatch_connect(struct session *t);
 const char *backend_lb_algo_str(int algo);
-int backend_parse_balance(const char **args, char *err,
-			  int errlen, struct proxy *curproxy);
+int backend_parse_balance(const char **args, char **err, struct proxy *curproxy);
 int tcp_persist_rdp_cookie(struct session *s, struct buffer *req, int an_bit);
 
 int be_downtime(struct proxy *px);