diff --git a/sysdep/unix/config.Y b/sysdep/unix/config.Y
index 5c4b5bef..fce64794 100644
--- a/sysdep/unix/config.Y
+++ b/sysdep/unix/config.Y
@@ -19,7 +19,7 @@ CF_DECLS
 
 CF_KEYWORDS(LOG, SYSLOG, ALL, DEBUG, TRACE, INFO, REMOTE, WARNING, ERROR, AUTH, FATAL, BUG, STDERR, SOFT)
 CF_KEYWORDS(NAME, CONFIRM, UNDO, CHECK, TIMEOUT, DEBUG, LATENCY, LIMIT, WATCHDOG, WARNING, STATUS)
-CF_KEYWORDS(GRACEFUL, RESTART)
+CF_KEYWORDS(GRACEFUL, RESTART, THREADS)
 
 %type <i> log_mask log_mask_list log_cat cfg_timeout
 %type <t> cfg_name
@@ -28,6 +28,9 @@ CF_KEYWORDS(GRACEFUL, RESTART)
 
 CF_GRAMMAR
 
+/* Dummy threads setting for forward compatibility */
+conf: THREADS expr ';' ;
+
 conf: log_config ;
 
 log_begin: { this_log = cfg_allocz(sizeof(struct log_config)); };