diff --git a/.github/workflows/stable.yml b/.github/workflows/stable.yml
index aa06b2d1..b03097f8 100644
--- a/.github/workflows/stable.yml
+++ b/.github/workflows/stable.yml
@@ -9,7 +9,7 @@ jobs:
     strategy:
       fail-fast: false
       matrix:
-        ruby: [2.7, '3.0', 3.1, 3.2, ruby-head, jruby-9.4]
+        ruby: [2.7, '3.0', 3.1, 3.2, ruby-head, jruby-9.4, truffleruby]
 
     env:
       BUNDLE_WITHOUT: "benchmark"
@@ -27,3 +27,8 @@ jobs:
 
       - name: Run tests
         run: bundle exec rake
+        if: matrix.ruby != 'truffleruby'
+
+      - name: Run specs (truffleruby)
+        run: bundle exec rake spec
+        if: matrix.ruby == 'truffleruby'
diff --git a/.github/workflows/unstable.yml b/.github/workflows/unstable.yml
index 0a968a0d..afea2a31 100644
--- a/.github/workflows/unstable.yml
+++ b/.github/workflows/unstable.yml
@@ -11,7 +11,7 @@ jobs:
     strategy:
       fail-fast: false
       matrix:
-        ruby: [ruby-head, jruby-head]
+        ruby: [ruby-head, jruby-head, truffleruby-head]
 
     env:
       BUNDLE_WITHOUT: "benchmark"
@@ -28,3 +28,8 @@ jobs:
 
       - name: Run tests
         run: bundle exec rake
+        if: matrix.ruby != 'truffleruby-head'
+
+      - name: Run specs (truffleruby)
+        run: bundle exec rake spec
+        if: matrix.ruby == 'truffleruby-head'
diff --git a/spec/return_codes_spec.rb b/spec/return_codes_spec.rb
index e3656b3a..e2b3fefe 100644
--- a/spec/return_codes_spec.rb
+++ b/spec/return_codes_spec.rb
@@ -34,6 +34,7 @@
         end
 
         it "prints a message to STDERR" do
+          skip "fails on truffleruby" if RUBY_ENGINE == "truffleruby" && command.include?("testunit_bad.rb")
           expect(@stderr).to match(/stopped.+SimpleCov.+previous.+error/i)
         end
       end