diff --git a/.github/workflows/devcontainer.yml b/.github/workflows/devcontainer.yml
index e110903..b311974 100644
--- a/.github/workflows/devcontainer.yml
+++ b/.github/workflows/devcontainer.yml
@@ -21,5 +21,5 @@ jobs:
             uname -a
             lsb_release -a
             ruby --version
-            bundle exec rake spec
+            SPEC_OPTS="--format documentation" bundle exec rake spec
             bundle exec rubocop