diff --git a/activerecord/lib/active_record/attribute_methods/read.rb b/activerecord/lib/active_record/attribute_methods/read.rb
index 90701938e5..3c03cce838 100644
--- a/activerecord/lib/active_record/attribute_methods/read.rb
+++ b/activerecord/lib/active_record/attribute_methods/read.rb
@@ -32,21 +32,29 @@ def cache_attribute?(attr_name)
 
         protected
 
-        # We want to generate the methods via module_eval rather than define_method,
-        # because define_method is slower on dispatch and uses more memory (because it
-        # creates a closure).
+        # We want to generate the methods via module_eval rather than
+        # define_method, because define_method is slower on dispatch and
+        # uses more memory (because it creates a closure).
         #
-        # But sometimes the database might return columns with characters that are not
-        # allowed in normal method names (like 'my_column(omg)'. So to work around this
-        # we first define with the __temp__ identifier, and then use alias method to
-        # rename it to what we want.
-        def define_method_attribute(attr_name)
+        # But sometimes the database might return columns with
+        # characters that are not allowed in normal method names (like
+        # 'my_column(omg)'. So to work around this we first define with
+        # the __temp__ identifier, and then use alias method to rename
+        # it to what we want.
+        #
+        # We are also defining a constant to hold the frozen string of
+        # the attribute name. Using a constant means that we do not have
+        # to allocate an object on each call to the attribute method.
+        # Making it frozen means that it doesn't get duped when used to
+        # key the @attributes_cache in read_attribute.
+        def define_method_attribute(name)
+          safe_name = name.unpack('h*').first
           generated_attribute_methods.module_eval <<-STR, __FILE__, __LINE__ + 1
-            def __temp__
-              read_attribute('#{attr_name}') { |n| missing_attribute(n, caller) }
+            def __temp__#{safe_name}
+              read_attribute(AttrNames::ATTR_#{safe_name}) { |n| missing_attribute(n, caller) }
             end
-            alias_method '#{attr_name}', :__temp__
-            undef_method :__temp__
+            alias_method #{name.inspect}, :__temp__#{safe_name}
+            undef_method :__temp__#{safe_name}
           STR
         end
 
diff --git a/activerecord/lib/active_record/attribute_methods/write.rb b/activerecord/lib/active_record/attribute_methods/write.rb
index fa9097db1f..cd33494cc3 100644
--- a/activerecord/lib/active_record/attribute_methods/write.rb
+++ b/activerecord/lib/active_record/attribute_methods/write.rb
@@ -9,15 +9,19 @@ module Write
 
       module ClassMethods
         protected
-          def define_method_attribute=(attr_name)
-            if attr_name =~ ActiveModel::AttributeMethods::NAME_COMPILABLE_REGEXP
-              generated_attribute_methods.module_eval("def #{attr_name}=(new_value); write_attribute('#{attr_name}', new_value); end", __FILE__, __LINE__)
-            else
-              generated_attribute_methods.send(:define_method, "#{attr_name}=") do |new_value|
-                write_attribute(attr_name, new_value)
-              end
+
+        # See define_method_attribute in read.rb for an explanation of
+        # this code.
+        def define_method_attribute=(name)
+          safe_name = name.unpack('h*').first
+          generated_attribute_methods.module_eval <<-STR, __FILE__, __LINE__ + 1
+            def __temp__#{safe_name}=(value)
+              write_attribute(AttrNames::ATTR_#{safe_name}, value)
             end
-          end
+            alias_method #{(name + '=').inspect}, :__temp__#{safe_name}=
+            undef_method :__temp__#{safe_name}=
+          STR
+        end
       end
 
       # Updates the attribute identified by <tt>attr_name</tt> with the
diff --git a/activerecord/lib/active_record/core.rb b/activerecord/lib/active_record/core.rb
index 957027c1ee..94c6684700 100644
--- a/activerecord/lib/active_record/core.rb
+++ b/activerecord/lib/active_record/core.rb
@@ -83,7 +83,12 @@ def initialize_generated_modules
         @attribute_methods_mutex = Mutex.new
 
         # force attribute methods to be higher in inheritance hierarchy than other generated methods
-        generated_attribute_methods
+        generated_attribute_methods.const_set(:AttrNames, Module.new {
+          def self.const_missing(name)
+            const_set(name, [name.to_s.sub(/ATTR_/, '')].pack('h*').freeze)
+          end
+        })
+
         generated_feature_methods
       end