diff --git a/actionpack/lib/action_dispatch/journey/visitors.rb b/actionpack/lib/action_dispatch/journey/visitors.rb
index 05ad619139..307830aa93 100644
--- a/actionpack/lib/action_dispatch/journey/visitors.rb
+++ b/actionpack/lib/action_dispatch/journey/visitors.rb
@@ -1,14 +1,10 @@
 # encoding: utf-8
 
-require 'thread_safe'
-
 module ActionDispatch
   module Journey # :nodoc:
     module Visitors # :nodoc:
       class Visitor # :nodoc:
-        DISPATCH_CACHE = ThreadSafe::Cache.new { |h,k|
-          h[k] = :"visit_#{k}"
-        }
+        DISPATCH_CACHE = {}
 
         def accept(node)
           visit(node)
@@ -38,8 +34,14 @@ module ActionDispatch
           def visit_STAR(n); unary(n); end
 
           def terminal(node); end
-          %w{ LITERAL SYMBOL SLASH DOT }.each do |t|
-            class_eval %{ def visit_#{t}(n); terminal(n); end }, __FILE__, __LINE__
+          def visit_LITERAL(n); terminal(n); end
+          def visit_SYMBOL(n);  terminal(n); end
+          def visit_SLASH(n);   terminal(n); end
+          def visit_DOT(n);     terminal(n); end
+
+          private_instance_methods(false).each do |pim|
+            next unless pim =~ /^visit_(.*)$/
+            DISPATCH_CACHE[$1.to_sym] = pim
           end
       end