diff --git a/ci/Dockerfile b/ci/Dockerfile
index f9ab2e1b..61f3bfe8 100644
--- a/ci/Dockerfile
+++ b/ci/Dockerfile
@@ -7,7 +7,7 @@ ARG SOPS_VERSION=3.9.4
 ARG KUBECTL_VERSION=1.34.0
 ARG VAULT_VERSION=1.18.1
 
-# Install system packages (single layer)
+# Install system packages (single layer).
 # python3: required by scripts/check-ingress-auth-comments.py, invoked
 #   by scripts/tg before every plan/apply.
 RUN apk add --no-cache \