diff --git a/CHANGES b/CHANGES
index 417921d1120cc77edf1f7f96bc87010ffe744b5f..c915ec1ef3164252c0c3a3e9b54b0f7f37f1ebff 100644
--- a/CHANGES
+++ b/CHANGES
@@ -11,6 +11,7 @@ OpenLDAP 2.4.11 Engineering
 	Fixed slapd configContext OID (ITS#5383)
 	Fixed slapd crash with no listeners (ITS#5563)
 	Fixed slapd equality rules for olcRootDN/olcSchemaDN (ITS#5540)
+	Fixed slapd syncrepl contextCSN updates as internal ops (ITS#5596)
 	Fixed slapd sets memory leak (ITS#5557)
 	Fixed slapd-meta link to slapd-ldap (ITS#5355)
 	Fixed slapd-sock, back-shell buffer count (ITS#5558)
diff --git a/servers/slapd/syncrepl.c b/servers/slapd/syncrepl.c
index 747435d8b1e5609264ca8579fb66c475283c8005..fd8847727c0a09a3571d82ec7b7505f8be0cff68 100644
--- a/servers/slapd/syncrepl.c
+++ b/servers/slapd/syncrepl.c
@@ -2733,6 +2733,7 @@ syncrepl_updateCookie(
 	mod.sml_op = LDAP_MOD_REPLACE;
 	mod.sml_desc = slap_schema.si_ad_contextCSN;
 	mod.sml_type = mod.sml_desc->ad_cname;
+	mod.sml_flags = SLAP_MOD_INTERNAL;
 	mod.sml_nvalues = NULL;
 	mod.sml_next = NULL;