diff --git a/schema/mysql/upgrades/1.3.0.sql b/schema/mysql/upgrades/1.3.0.sql
index 047903807..5065e9483 100644
--- a/schema/mysql/upgrades/1.3.0.sql
+++ b/schema/mysql/upgrades/1.3.0.sql
@@ -8,11 +8,11 @@ ALTER TABLE notification MODIFY COLUMN properties_checksum binary(20) NOT NULL C
 ALTER TABLE timeperiod_range MODIFY COLUMN range_value text NOT NULL;
 
 ALTER TABLE checkcommand_argument MODIFY COLUMN argument_key varchar(255) NOT NULL;
-ALTER TABLE checkcommand_argument MODIFY COLUMN argument_key_override varchar(255) NOT NULL;
+ALTER TABLE checkcommand_argument MODIFY COLUMN argument_key_override varchar(255) COLLATE utf8mb4_unicode_ci DEFAULT NULL;
 ALTER TABLE eventcommand_argument MODIFY COLUMN argument_key varchar(255) NOT NULL;
-ALTER TABLE eventcommand_argument MODIFY COLUMN argument_key_override varchar(255) NOT NULL;
+ALTER TABLE eventcommand_argument MODIFY COLUMN argument_key_override varchar(255) COLLATE utf8mb4_unicode_ci DEFAULT NULL;
 ALTER TABLE notificationcommand_argument MODIFY COLUMN argument_key varchar(255) NOT NULL;
-ALTER TABLE notificationcommand_argument MODIFY COLUMN argument_key_override varchar(255) NOT NULL;
+ALTER TABLE notificationcommand_argument MODIFY COLUMN argument_key_override varchar(255) COLLATE utf8mb4_unicode_ci DEFAULT NULL;
 
 ALTER TABLE checkcommand_envvar MODIFY COLUMN envvar_key varchar(255) NOT NULL;
 ALTER TABLE eventcommand_envvar MODIFY COLUMN envvar_key varchar(255) NOT NULL;