diff --git a/.github/workflows/Specs.yml b/.github/workflows/Specs.yml
index a2068df..9e64d20 100644
--- a/.github/workflows/Specs.yml
+++ b/.github/workflows/Specs.yml
@@ -6,7 +6,7 @@ jobs:
       fail-fast: false
       matrix:
         os: [macos-10.15]
-        ruby: [2.3, 2.5, 2.6, 2.7]
+        ruby: [2.3, 2.5, 2.6, 2.7, 3.0]
 
     name: ${{ matrix.os }} / Ruby ${{ matrix.ruby }}
     runs-on: ${{ matrix.os }}
diff --git a/Gemfile b/Gemfile
index fe75175..3ffcbcc 100644
--- a/Gemfile
+++ b/Gemfile
@@ -8,6 +8,7 @@ group :development do
   gem 'mocha-on-bacon'
   gem 'prettybacon'
   gem 'rake'
+  gem 'rexml', '~> 3.2.4'
   gem 'vcr'
   gem 'webmock', '< 1.9'
 
diff --git a/Gemfile.lock b/Gemfile.lock
index 9dfeb6a..0a47fa2 100644
--- a/Gemfile.lock
+++ b/Gemfile.lock
@@ -44,6 +44,7 @@ GEM
       ffi (>= 0.5.0)
     rb-kqueue (0.2.3)
       ffi (>= 0.5.0)
+    rexml (3.2.4)
     rubocop (0.38.0)
       parser (>= 2.3.0.6, < 3.0)
       powerpack (~> 0.1)
@@ -57,7 +58,7 @@ GEM
       multi_json (~> 1.0)
       simplecov-html (~> 0.8.0)
     simplecov-html (0.8.0)
-    unicode-display_width (1.0.2)
+    unicode-display_width (1.7.0)
     vcr (2.9.3)
     webmock (1.8.11)
       addressable (>= 2.2.7)
@@ -75,6 +76,7 @@ DEPENDENCIES
   mocha-on-bacon
   prettybacon
   rake
+  rexml (~> 3.2.4)
   rubocop
   simplecov
   vcr