diff --git a/activesupport/lib/active_support/core_ext/module/attribute_accessors_per_thread.rb b/activesupport/lib/active_support/core_ext/module/attribute_accessors_per_thread.rb
index 045668c207..ff4294a991 100644
--- a/activesupport/lib/active_support/core_ext/module/attribute_accessors_per_thread.rb
+++ b/activesupport/lib/active_support/core_ext/module/attribute_accessors_per_thread.rb
@@ -3,7 +3,7 @@
 # Extends the module object with class/module and instance accessors for
 # class/module attributes, just like the native attr* accessors for instance
 # attributes, but does so on a per-thread basis.
-# 
+#
 # So the values are scoped within the Thread.current space under the class name
 # of the module.
 class Module
@@ -133,9 +133,9 @@ def #{sym}=(obj)
   #
   #   Current.new.user = "DHH"  # => NoMethodError
   #   Current.new.user          # => NoMethodError
-  def thread_mattr_accessor(*syms, &blk)
-    thread_mattr_reader(*syms, &blk)
-    thread_mattr_writer(*syms, &blk)
+  def thread_mattr_accessor(*syms)
+    thread_mattr_reader(*syms)
+    thread_mattr_writer(*syms)
   end
   alias :thread_cattr_accessor :thread_mattr_accessor
 end