diff --git a/dockerfile-captain.edge b/dockerfile-captain.edge
index 393c4e3..85b8b51 100644
--- a/dockerfile-captain.edge
+++ b/dockerfile-captain.edge
@@ -17,7 +17,7 @@ RUN npm ci && \
 
 # Build frontend code
 
- # This quick hack invalidates the cache
+ # This quick hack invalidates the cache.
 ADD https://www.google.com /time.now
 
 # armV7 fails: https://github.com/yarnpkg/yarn/issues/5259 https://github.com/nodejs/docker-node/issues/1335