diff --git a/.github/workflows/development.yml b/.github/workflows/development.yml
index 4af5680a0..c13796d2c 100644
--- a/.github/workflows/development.yml
+++ b/.github/workflows/development.yml
@@ -8,7 +8,7 @@ jobs:
       fail-fast: false
       matrix:
         os: [ubuntu-latest, macos-latest]
-        ruby: [2.4, 2.5, 2.6, 2.7, jruby, truffleruby-head]
+        ruby: [2.4, 2.5, 2.6, 2.7, 3.0, jruby, truffleruby-head]
     runs-on: ${{matrix.os}}
     steps:
     - uses: actions/checkout@v2
diff --git a/Gemfile b/Gemfile
index 31076afbd..186aefc47 100644
--- a/Gemfile
+++ b/Gemfile
@@ -4,6 +4,7 @@ source 'https://rubygems.org'
 
 gemspec
 
+gem "webrick"
 gem "rubocop", require: false
 gem "rubocop-packaging", require: false