diff --git a/appveyor.yml b/appveyor.yml
index a2436ab181..ee2e033a6f 100644
--- a/appveyor.yml
+++ b/appveyor.yml
@@ -3,6 +3,7 @@ pull_requests:
   do_not_increment_build_number: true
 environment:
   TGS4_TEST_DATABASE_TYPE: SqlServer
+  TGS4_TEST_DUMP_API_SPEC: yes
   TGS4_TEST_CONNECTION_STRING: Server=(local)\SQL2017;Initial Catalog=TGS_Test;User ID=sa;Password=Password12!
   TGS4_TEST_GITHUB_TOKEN:
     secure: lJNGAXwiB5HlWdthz3K4PetqpTG5IEAyRgKaiKxFMQ8HW8CcOjRtB97B05op7BsK