diff --git a/lib/acts_as_taggable_on/acts_as_taggable_on/core.rb b/lib/acts_as_taggable_on/acts_as_taggable_on/core.rb
index 1d32b375c..fa25c9adc 100644
--- a/lib/acts_as_taggable_on/acts_as_taggable_on/core.rb
+++ b/lib/acts_as_taggable_on/acts_as_taggable_on/core.rb
@@ -307,7 +307,7 @@ def tagging_contexts
       end
 
       def process_dirty_object(context,new_list)
-        value = new_list.is_a?(Array) ? new_list.join(', ') : new_list
+        value = new_list.is_a?(Array) ? ActsAsTaggableOn::TagList.new(new_list) : new_list
         attrib = "#{context.to_s.singularize}_list"
 
         if changed_attributes.include?(attrib)
diff --git a/spec/acts_as_taggable_on/taggable_spec.rb b/spec/acts_as_taggable_on/taggable_spec.rb
index bb919df6a..851a31819 100644
--- a/spec/acts_as_taggable_on/taggable_spec.rb
+++ b/spec/acts_as_taggable_on/taggable_spec.rb
@@ -562,6 +562,22 @@
         it 'does not show any changes to the taggable item' do
           @taggable.changes.should == {}
         end
+
+        context "and using a delimiter different from a ','" do
+          before do
+            @old_delimiter = ActsAsTaggableOn.delimiter
+            ActsAsTaggableOn.delimiter = ';'
+          end
+
+          after do
+            ActsAsTaggableOn.delimiter = @old_delimiter
+          end
+
+          it 'does not show any changes to the taggable item when using array assignments' do
+            @taggable.tag_list = ["awesome", "epic"]
+            @taggable.changes.should == {}
+          end
+        end
       end
     end