diff --git a/lib/acts_as_versioned.rb b/lib/acts_as_versioned.rb
index 6e5ef5d..87e6fc0 100644
--- a/lib/acts_as_versioned.rb
+++ b/lib/acts_as_versioned.rb
@@ -392,10 +392,12 @@ def next_version
           def clear_changed_attributes
             self.changed_attributes = []
           end
-          
+
           def write_changed_attribute(attr_name, attr_value)
-            (self.changed_attributes ||= []) << attr_name.to_s unless self.changed?(attr_name) or self.send(attr_name) == attr_value
-            write_attribute(attr_name.to_s, attr_value)
+            # Convert to db type for comparison. Avoids failing Float<=>String comparisons.
+            attr_value_for_db = self.class.columns_hash[attr_name.to_s].type_cast(attr_value)
+            (self.changed_attributes ||= []) << attr_name.to_s unless self.changed?(attr_name) || self.send(attr_name) == attr_value_for_db
+            write_attribute(attr_name, attr_value_for_db)
           end
 
         private
diff --git a/test/schema.rb b/test/schema.rb
index 7ae09bc..7d5153d 100644
--- a/test/schema.rb
+++ b/test/schema.rb
@@ -50,4 +50,19 @@
     t.column :version, :integer
     t.column :updated_at, :datetime
   end
-end
\ No newline at end of file
+  
+  create_table :landmarks, :force => true do |t|
+    t.column :name, :string
+    t.column :latitude, :float
+    t.column :longitude, :float
+    t.column :version, :integer
+  end
+
+  create_table :landmark_versions, :force => true do |t|
+    t.column :landmark_id, :integer
+    t.column :name, :string
+    t.column :latitude, :float
+    t.column :longitude, :float
+    t.column :version, :integer
+  end
+end
diff --git a/test/versioned_test.rb b/test/versioned_test.rb
index 7259ffb..c1e1a4b 100644
--- a/test/versioned_test.rb
+++ b/test/versioned_test.rb
@@ -3,7 +3,7 @@
 require File.join(File.dirname(__FILE__), 'fixtures/widget')
 
 class VersionedTest < Test::Unit::TestCase
-  fixtures :pages, :page_versions, :locked_pages, :locked_pages_revisions, :authors
+  fixtures :pages, :page_versions, :locked_pages, :locked_pages_revisions, :authors, :landmarks, :landmark_versions
 
   def test_saves_versioned_copy
     p = Page.create :title => 'first title', :body => 'first body'
@@ -300,4 +300,14 @@ def test_versioned_records_should_belong_to_parent
     page_version = page.versions.last
     assert_equal page, page_version.page
   end
+  
+  def test_unchanged_attributes
+    landmarks(:washington).attributes = landmarks(:washington).attributes
+    assert !landmarks(:washington).changed?
+  end
+  
+  def test_unchanged_string_attributes
+    landmarks(:washington).attributes = landmarks(:washington).attributes.inject({}) { |params, (key, value)| params.update key => value.to_s }
+    assert !landmarks(:washington).changed?
+  end
 end