diff --git a/core/model/src/test/groovy/au/com/dius/pact/core/model/generators/DateTimeGeneratorSpec.groovy b/core/model/src/test/groovy/au/com/dius/pact/core/model/generators/DateTimeGeneratorSpec.groovy
index 26b1de3df3..fb6a97f6f3 100644
--- a/core/model/src/test/groovy/au/com/dius/pact/core/model/generators/DateTimeGeneratorSpec.groovy
+++ b/core/model/src/test/groovy/au/com/dius/pact/core/model/generators/DateTimeGeneratorSpec.groovy
@@ -37,6 +37,6 @@ class DateTimeGeneratorSpec extends Specification {
   def 'supports timezones with zone IDs'() {
     expect:
     new DateTimeGenerator("yyyy-MM-dd'T'HH:mm:ssZ'['VV']'", null).generate([:]) ==~
-      /\d{4}-\d{2}-\d{2}T\d{2}:\d{2}:\d{2}[-+]\d+\[\w+\/\w+]/
+      /\d{4}-\d{2}-\d{2}T\d{2}:\d{2}:\d{2}[-+]\d+\[\w+(\/\w+)?]/
   }
 }