diff --git a/kernel/common/module.rb b/kernel/common/module.rb
index ee33482b53..d6d67b3c8a 100644
--- a/kernel/common/module.rb
+++ b/kernel/common/module.rb
@@ -47,7 +47,7 @@ def verify_class_variable_name(name)
   end
   private :verify_class_variable_name
 
-  def class_variable_set(name, val)
+  def __class_variable_set__(name, val)
     Rubinius.primitive :module_cvar_set
 
     class_variable_set verify_class_variable_name(name), val
diff --git a/kernel/common/module18.rb b/kernel/common/module18.rb
index 9f7949d037..8e6f4b46c1 100644
--- a/kernel/common/module18.rb
+++ b/kernel/common/module18.rb
@@ -25,4 +25,6 @@ def attr(name, writeable = false)
   end
 
   private :attr
+  
+  alias_method :class_variable_set, :__class_variable_set__
 end
diff --git a/kernel/common/module19.rb b/kernel/common/module19.rb
index 4b1485b529..27b10a63ff 100644
--- a/kernel/common/module19.rb
+++ b/kernel/common/module19.rb
@@ -40,4 +40,9 @@ def attr(*attributes)
   end
 
   private :attr
+  
+  def class_variable_set(key, value)
+    raise RuntimeError, "can't modify frozen #{self.class}" if frozen?
+    __class_variable_set__(key, value)
+  end
 end
diff --git a/spec/tags/19/ruby/core/module/class_variable_set_tags.txt b/spec/tags/19/ruby/core/module/class_variable_set_tags.txt
deleted file mode 100644
index d58029cc4f..0000000000
--- a/spec/tags/19/ruby/core/module/class_variable_set_tags.txt
+++ /dev/null
@@ -1 +0,0 @@
-fails:Module#class_variable_set raises a RuntimeError when self is frozen