diff --git a/.github/workflows/test.yml b/.github/workflows/test.yml
index d253c5de73b7df355d093573b752e073718fdd25..db1e45e0cf74a52f2f85170dffdb6a37f1fe0c46 100644
--- a/.github/workflows/test.yml
+++ b/.github/workflows/test.yml
@@ -27,7 +27,7 @@ jobs:
           ruby-version: '2.4.x'
           
       - name: Set up Bundler
-        run: gem install bundler -v "~> 2.0"
+        run: gem install bundler -v "~> 1.17"
           
       - run: ruby --version
       - run: gem --version
diff --git a/Gemfile b/Gemfile
index 6d78e3d0909fb780bdd4a9ed59393349d57c3394..9d37be51469d6ede57cfb31343364c4ae2ef1b55 100644
--- a/Gemfile
+++ b/Gemfile
@@ -1,9 +1,5 @@
-# frozen_string_literal: true
-
 source "https://rubygems.org"
 
-git_source(:github) {|repo_name| "https://github.com/#{repo_name}" }
-
 gem "jekyll", "~> 4.0"
 
 group :jekyll_plugins do