diff --git a/src/libs/zbxdiag/diag.c b/src/libs/zbxdiag/diag.c
index ee4e236e83..583c1b252a 100644
--- a/src/libs/zbxdiag/diag.c
+++ b/src/libs/zbxdiag/diag.c
@@ -500,7 +500,7 @@ void	diag_add_locks_info(struct zbx_json *json)
 	const char	*names[ZBX_MUTEX_COUNT] = {"ZBX_MUTEX_LOG", "ZBX_MUTEX_CACHE", "ZBX_MUTEX_TRENDS",
 				"ZBX_MUTEX_CACHE_IDS", "ZBX_MUTEX_SELFMON", "ZBX_MUTEX_CPUSTATS", "ZBX_MUTEX_DISKSTATS",
 				"ZBX_MUTEX_ITSERVICES", "ZBX_MUTEX_VALUECACHE", "ZBX_MUTEX_VMWARE", "ZBX_MUTEX_SQLITE3",
-				"ZBX_MUTEX_PROCSTAT", "ZBX_MUTEX_PROXY_HISTORY", "ZBX_MUTEX_KSTAT"};
+				"ZBX_MUTEX_PROCSTAT", "ZBX_MUTEX_PROXY_HISTORY", "ZBX_MUTEX_KSTAT", "ZBX_MUTEX_MODBUS"};
 
 	zbx_json_addarray(json, ZBX_DIAG_LOCKS);