diff --git a/test/ruby/test_proc.rb b/test/ruby/test_proc.rb
index 69cb0e439b..9071b92f0e 100644
--- a/test/ruby/test_proc.rb
+++ b/test/ruby/test_proc.rb
@@ -1342,7 +1342,7 @@ class TestProc < Test::Unit::TestCase
   end
 
   def test_local_variable_set_wb
-    assert_ruby_status([], <<-'end;', '[Bug #13605]', timeout: 15)
+    assert_ruby_status([], <<-'end;', '[Bug #13605]', timeout: 20)
       b = binding
       n = 20_000