diff --git a/lib/parallel/forkmanager.rb b/lib/parallel/forkmanager.rb
index 0127894..897db65 100644
--- a/lib/parallel/forkmanager.rb
+++ b/lib/parallel/forkmanager.rb
@@ -736,6 +736,7 @@ def setup_instance_variables(max_procs, params)
     def check_ruby_version
       return if RUBY_VERSION.start_with?("1.9")
       return if RUBY_VERSION.start_with?("2.")
+      return if RUBY_VERSION.start_with?("3.")
       fail "Unsupported Ruby version #{RUBY_VERSION}!"
     end
   end # class