diff --git a/.github/workflows/test-pull-requests.yml b/.github/workflows/test-pull-requests.yml
index 813b0e8a..aa9009cf 100644
--- a/.github/workflows/test-pull-requests.yml
+++ b/.github/workflows/test-pull-requests.yml
@@ -6,12 +6,16 @@ jobs:
   test:
 
     runs-on: ubuntu-latest
+    strategy:
+      matrix:
+        ruby: [ '2.6', '2.7', '3.2' ]
 
+    name: Ruby ${{ matrix.ruby }} test
     steps:
     - uses: actions/checkout@v1
     - name: Set up Ruby 2.6
       uses: ruby/setup-ruby@v1
       with:
-        ruby-version: '2.6'
+        ruby-version: ${{ matrix.ruby }}
     - name: Run all tests
       run: make test
diff --git a/lib/jekyll-open-sdg-plugins/fetch_remote_data.rb b/lib/jekyll-open-sdg-plugins/fetch_remote_data.rb
index f578e6f7..3d065577 100644
--- a/lib/jekyll-open-sdg-plugins/fetch_remote_data.rb
+++ b/lib/jekyll-open-sdg-plugins/fetch_remote_data.rb
@@ -39,7 +39,7 @@ def fetch_build(path)
         endpoint = is_remote ? path + '/' + value : File.join(path, fix_path(value))
 
         begin
-          json_file = is_remote ? open(endpoint) : File.open(endpoint)
+          json_file = is_remote ? URI.open(endpoint) : File.open(endpoint)
           build[key] = JSON.load(json_file)
         rescue StandardError => e
           # For backwards compatibility, forego the exception in some cases.
diff --git a/tests/Gemfile b/tests/Gemfile
index 544a65ff..5cf1d1e8 100644
--- a/tests/Gemfile
+++ b/tests/Gemfile
@@ -1,7 +1,9 @@
 source "https://rubygems.org"
 
-gem "jekyll", "3.8.4"
-gem "html-proofer"
+gem "jekyll", "3.9.3"
+gem "html-proofer", "3.19.4"
 gem "jekyll-remote-theme"
 gem "deep_merge"
 gem "json_schemer"
+gem "kramdown-parser-gfm"
+gem "webrick"