diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index 340f60b..dd33abb 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -15,7 +15,7 @@ jobs:
       run: |
         docker run --rm \
         --volume="${{ github.workspace }}:/srv/jekyll" \
-        jekyll/builder:3.8.5 /bin/bash -c "chmod 777 /srv/jekyll && jekyll build"
+        jekyll/builder:latest /bin/bash -c "gem install bundler && chmod 777 /srv/jekyll && jekyll build"
         
   css:
     name: Stylelint
diff --git a/just-the-docs.gemspec b/just-the-docs.gemspec
index b03105b..2cd3991 100644
--- a/just-the-docs.gemspec
+++ b/just-the-docs.gemspec
@@ -12,10 +12,10 @@ Gem::Specification.new do |spec|
 
   spec.files         = `git ls-files -z`.split("\x0").select { |f| f.match(%r{^(assets|bin|_layouts|_includes|lib|Rakefile|_sass|LICENSE|README)}i) }
   spec.executables   << 'just-the-docs'
-
+  
+  spec.add_runtime_dependency "bundler", "~> 2.1.4"
   spec.add_runtime_dependency "jekyll", ">= 3.8.5", "< 4.1.0"
   spec.add_runtime_dependency "jekyll-seo-tag", "~> 2.0"
   spec.add_runtime_dependency "rake", "~> 12.3.1"
 
-  spec.add_development_dependency "bundler", "~> 2.0.1"
 end