diff --git a/activemodel/lib/active_model/attribute_methods.rb b/activemodel/lib/active_model/attribute_methods.rb
index 2a99450a3d..21ddef6b75 100644
--- a/activemodel/lib/active_model/attribute_methods.rb
+++ b/activemodel/lib/active_model/attribute_methods.rb
@@ -108,9 +108,8 @@ module ActiveModel
         else
           # use eval instead of a block to work around a memory leak in dev
           # mode in fcgi
-          sing.class_eval <<-eorb, __FILE__, __LINE__ + 1
-            def #{name}; #{value.nil? ? 'nil' : value.to_s.inspect}; end
-          eorb
+          value = value.nil? ? 'nil' : value.to_s
+          sing.send(:define_method, name) { value }
         end
       end
 
diff --git a/activemodel/test/cases/attribute_methods_test.rb b/activemodel/test/cases/attribute_methods_test.rb
index 13f29a8fd9..5cf905bc1f 100644
--- a/activemodel/test/cases/attribute_methods_test.rb
+++ b/activemodel/test/cases/attribute_methods_test.rb
@@ -7,7 +7,7 @@ class ModelWithAttributes
 
   class << self
     define_method(:bar) do
-      'bar'
+      'original bar'
     end
   end
 
@@ -49,7 +49,7 @@ class ModelWithWeirdNamesAttributes
 
   class << self
     define_method(:'c?d') do
-      'c?d'
+      'original c?d'
     end
   end
 
@@ -102,6 +102,7 @@ class AttributeMethodsTest < ActiveModel::TestCase
     ModelWithAttributes.define_attr_method(:bar, 'bar')
 
     assert_respond_to ModelWithAttributes, :bar
+    assert_equal "original bar", ModelWithAttributes.original_bar
     assert_equal "bar", ModelWithAttributes.bar
   end
 
@@ -109,6 +110,7 @@ class AttributeMethodsTest < ActiveModel::TestCase
     ModelWithWeirdNamesAttributes.define_attr_method(:'c?d', 'c?d')
 
     assert_respond_to ModelWithWeirdNamesAttributes, :'c?d'
+    assert_equal "original c?d", ModelWithWeirdNamesAttributes.send('original_c?d')
     assert_equal "c?d", ModelWithWeirdNamesAttributes.send('c?d')
   end