diff --git a/servers/slapd/schema_init.c b/servers/slapd/schema_init.c
index 7d7d1b26d9..cfaf519ea9 100644
--- a/servers/slapd/schema_init.c
+++ b/servers/slapd/schema_init.c
@@ -5401,8 +5401,8 @@ csnNormalize23(
 	}
 	*ptr = '\0';
 
-	assert( ptr == &bv.bv_val[bv.bv_len] );
-	if ( csnValidate( syntax, &bv ) != LDAP_SUCCESS ) {
+	if ( ptr != &bv.bv_val[bv.bv_len] ||
+		csnValidate( syntax, &bv ) != LDAP_SUCCESS ) {
 		return LDAP_INVALID_SYNTAX;
 	}