diff --git a/script/docker_test.rb b/script/docker_test.rb
index d51b63b5c57..1c50dd7cf55 100644
--- a/script/docker_test.rb
+++ b/script/docker_test.rb
@@ -23,7 +23,7 @@ unless ENV["NO_UPDATE"]
   run_or_fail("git reset --hard")
   run_or_fail("git fetch")
 
-  checkout = ENV["COMMIT_HASH"] || "FETCH_HEAD"
+  checkout = ENV["COMMIT_HASH"] || "origin/tests-passed"
   run_or_fail("LEFTHOOK=0 git checkout #{checkout}")
 
   run_or_fail("bundle")