I believe the setting should be hibernate.hbm2ddl.auto=create-only. [1]

Vlad Mihalcea, any idea where this is documented (other than Javadoc)? This may be new to 5.1.

[1] https://docs.jboss.org/hibernate/orm/5.1/javadocs/org/hibernate/tool/schema/Action.html#CREATE_ONLY