Grails 2.3 IntegrationSpec cannot be transactional false

I upgrade to Grails 2.3 recently and try to migrate all old tests to spock integration test. But it fails at cleanup because my test is non-transactional. The Grails doc says test can be non-transactional, but we need to handle it manually, but it seems not quite right here. as I am getting this error in every integration test extending IntegrationSpec

java.lang.IllegalStateException: Cannot deactivate transaction synchronization - not active
    at grails.test.spock.IntegrationSpec.cleanup(IntegrationSpec.groovy:72)

A simple test like this would throw that error:

import grails.test.spock.IntegrationSpec

public class DummySpec extends IntegrationSpec {
   static transactional = false

   def setup() {
   }

   def cleanup() {
   }

   def testDummy() {
      expect:
      1 == 1
   }
}