3 files changed, 10 insertions, 9 deletions
diff --git a/activemodel/lib/active_model/attribute_methods.rb b/activemodel/lib/active_model/attribute_methods.rb
index 44e3e64a9e..fc5f5c4c66 100644
--- a/activemodel/lib/active_model/attribute_methods.rb
+++ b/activemodel/lib/active_model/attribute_methods.rb
@@ -46,8 +46,8 @@ module ActiveModel
   #     end
   #   end
   #
-  # Notice that whenever you include ActiveModel::AttributeMethods in your class,
-  # it requires you to implement a <tt>attributes</tt> methods which returns a hash
+  # Note that whenever you include ActiveModel::AttributeMethods in your class,
+  # it requires you to implement an <tt>attributes</tt> method which returns a hash
   # with each attribute name in your model as hash key and the attribute value as
   # hash value.
   #
@@ -98,10 +98,10 @@ module ActiveModel
       def define_attr_method(name, value=nil, &block)
         sing = singleton_class
         sing.class_eval <<-eorb, __FILE__, __LINE__ + 1
-          if method_defined?(:original_#{name})
-            undef :original_#{name}
+          if method_defined?(:'original_#{name}')
+            undef :'original_#{name}'
           end
-          alias_method :original_#{name}, :#{name}
+          alias_method :'original_#{name}', :'#{name}'
         eorb
         if block_given?
           sing.send :define_method, name, &block
@@ -274,8 +274,8 @@ module ActiveModel
                 method_name = matcher.method_name(attr_name)
 
                 generated_attribute_methods.module_eval <<-STR, __FILE__, __LINE__ + 1
-                  if method_defined?(:#{method_name})
-                    undef :#{method_name}
+                  if method_defined?(:'#{method_name}')
+                    undef :'#{method_name}'
                   end
                   def #{method_name}(*args)
                     send(:#{matcher.method_missing_target}, '#{attr_name}', *args)
diff --git a/activemodel/lib/active_model/naming.rb b/activemodel/lib/active_model/naming.rb
index adb71f788f..44aedc8efd 100644
--- a/activemodel/lib/active_model/naming.rb
+++ b/activemodel/lib/active_model/naming.rb
@@ -1,5 +1,6 @@
 require 'active_support/inflector'
 require 'active_support/core_ext/hash/except'
+require 'active_support/core_ext/module/introspection'
 
 module ActiveModel
   class Name < String
diff --git a/activemodel/lib/active_model/version.rb b/activemodel/lib/active_model/version.rb
index ece4431225..23ba42bf35 100644
--- a/activemodel/lib/active_model/version.rb
+++ b/activemodel/lib/active_model/version.rb
@@ -3,8 +3,8 @@ module ActiveModel
     MAJOR = 3
     MINOR = 1
     TINY  = 0
-    BUILD = "beta"
+    PRE   = "beta"
 
-    STRING = [MAJOR, MINOR, TINY, BUILD].join('.')
+    STRING = [MAJOR, MINOR, TINY, PRE].compact.join('.')
   end
 end