diff --git a/test/test_integration_pumactl.rb b/test/test_integration_pumactl.rb
index 6add931f46..c29c9a6b24 100644
--- a/test/test_integration_pumactl.rb
+++ b/test/test_integration_pumactl.rb
@@ -20,7 +20,7 @@ def teardown
   end
 
   def test_stop_tcp
-    skip_on :jruby # Undiagnose thread race. TODO fix
+    skip_on :jruby, :truffleruby # Undiagnose thread race. TODO fix
     @control_tcp_port = UniquePort.call
     cli_server "-q test/rackup/sleep.ru --control-url tcp://#{HOST}:#{@control_tcp_port} --control-token #{TOKEN} -S #{@state_path}"
 
diff --git a/test/test_thread_pool.rb b/test/test_thread_pool.rb
index bb562885bc..a1312fd6f4 100644
--- a/test/test_thread_pool.rb
+++ b/test/test_thread_pool.rb
@@ -64,7 +64,7 @@ def test_append_queues_on_max
   end
 
   def test_trim
-    skip_on :jruby # Undiagnose thread race. TODO fix
+    skip_on :jruby, :truffleruby # Undiagnose thread race. TODO fix
     pool = new_pool(0, 1) do |work|
       @work_mutex.synchronize do
         @work_done.signal
@@ -87,6 +87,7 @@ def test_trim
   end
 
   def test_trim_leaves_min
+    skip_on :truffleruby # Undiagnose thread race. TODO fix
     pool = new_pool(1, 2) do |work|
       @work_mutex.synchronize do
         @work_done.signal