diff --git a/.devcontainer/Dockerfile b/.devcontainer/Dockerfile
index 0355f00d..b3d0e9ad 100644
--- a/.devcontainer/Dockerfile
+++ b/.devcontainer/Dockerfile
@@ -21,4 +21,6 @@ RUN \
   && \
   curl -fsSL https://raw.githubusercontent.com/helm/helm/master/scripts/get-helm-3 | /bin/bash - \
   && \
-  bundle install --gemfile /tmp/Gemfile
+  bundle config set system 'true' \
+  && bundle install --gemfile /tmp/Gemfile \
+  && rm /tmp/Gemfile
diff --git a/Gemfile b/Gemfile
index ac5b8e73..f4cb5d56 100644
--- a/Gemfile
+++ b/Gemfile
@@ -4,9 +4,9 @@ source 'https://rubygems.org'
 
 group :test do
   gem 'm'
-  gem 'minitest'
+  gem 'minitest', "5.14.2"
   gem 'minitest-implicit-subject'
-  gem 'minitest-reporters'
-  gem 'pry'
+  gem 'minitest-reporters', "1.4.2"
+  gem 'pry', "0.13.1"
   gem 'ruby-jq'
 end