addNotNullConstraint not detected in version 4.20.0

I recently updated to from org.liquibase/liquibase-core 4.11.0 to 4.20.0 and when I run my migration tests I get an exception with the following error message:

liquibase.exception.ChangeLogParseException: Error parsing liquibase.yaml
...
Caused by: liquibase.exception.SetupException: Error parsing migrations/000_migrations.yaml
...
Caused by: liquibase.exception.ChangeLogParseException: Error parsing migrations/000_migrations.yaml
...
Caused by: liquibase.parser.core.ParsedNodeException: Error parsing migrations/000_migrations.yaml: Unknown change type 'addNotNullContstraint'. Check for spelling or capitalization errors and missing extensions such as liquibase-commercial.
...

I’ve put in … where the large stack traces go, but ultimately it seems like version 20 isn’t seeing the addNotNullContstraint for some reason.

The relevant part of my migration looks like this:

        - addNotNullConstraint:
            columnDataType: text
            columnName: parameters
            defaultNullValue: '[]'
            tableName: report_dashboard

Any ideas as to why it isn’t working?