diff --git a/test/ruby/ruby_specs_test.rb b/test/ruby/ruby_specs_test.rb
index 1b2b6d66f7..d4172de46e 100644
--- a/test/ruby/ruby_specs_test.rb
+++ b/test/ruby/ruby_specs_test.rb
@@ -7,8 +7,13 @@
 describe 'ruby/spec' do
   parallelize_me!
 
-  def spec_timeout
-    (ENV['SPEC_TIMEOUT'] || 120).to_i
+  def spec_timeout(path)
+    case path
+    when %r{core/thread}
+      240
+    else
+      120
+    end
   end
 
   Dir.chdir File.expand_path('../..', __dir__)
@@ -19,7 +24,7 @@ def spec_timeout
          elsif !(glob = ENV['GLOB']).to_s.empty?
            # GLOB="spec/core/io/*_spec.rb,spec/core/thread/*_spec.rb" rake test
            Dir[*glob.split(',')].tap do |files|
-             puts "Matched files:"
+             puts 'Matched files:'
              puts files.to_a
            end
          else
@@ -28,7 +33,7 @@ def spec_timeout
   glob.each do |path|
     describe path do
       it 'passes all specs' do
-        out_nat = Timeout.timeout(spec_timeout, nil, "execution expired running: #{path}") do
+        out_nat = Timeout.timeout(spec_timeout(path), nil, "execution expired running: #{path}") do
           `#{NAT_BINARY} #{path} 2>&1`
         end
         puts out_nat if ENV['DEBUG'] || !$?.success?
diff --git a/test/support/compare_rubies.rb b/test/support/compare_rubies.rb
index b2489bf0cf..f5b53a7a15 100644
--- a/test/support/compare_rubies.rb
+++ b/test/support/compare_rubies.rb
@@ -1,7 +1,7 @@
 require 'timeout'
 
 module CompareRubies
-  SPEC_TIMEOUT = (ENV['SPEC_TIMEOUT'] || 240).to_i
+  SPEC_TIMEOUT = 240
   NAT_BINARY = ENV['NAT_BINARY'] || 'bin/natalie'
 
   def run_nat(path, *args)