diff --git a/tools/docker/Dockerfile b/tools/docker/Dockerfile
index 8e0a3de..16a205e 100644
--- a/tools/docker/Dockerfile
+++ b/tools/docker/Dockerfile
@@ -8,4 +8,5 @@ RUN apk update \
       && apk add --virtual build-dependencies build-base \
       && bundle install \
       && gem build wrapture.gemspec \
-      && gem install wrapture-*.gem
+      && gem install wrapture-*.gem \
+      && apk del build-dependencies