diff --git a/app/models/issue.rb b/app/models/issue.rb
index ae3dd10..c474860 100644
--- a/app/models/issue.rb
+++ b/app/models/issue.rb
@@ -233,7 +233,7 @@ class Issue < ActiveRecord::Base
   # Copies attributes from another issue, arg can be an id or an Issue
   def copy_from(arg, options={})
     issue = arg.is_a?(Issue) ? arg : Issue.visible.find(arg)
-    self.attributes = issue.attributes.dup.except("id", "root_id", "parent_id", "lft", "rgt", "created_on", "updated_on")
+    self.attributes = issue.attributes.dup.except("id", "root_id", "parent_id", "lft", "rgt", "created_on", "updated_on", "closed_on")
     self.custom_field_values = issue.custom_field_values.inject({}) {|h,v| h[v.custom_field_id] = v.value; h}
     self.status = issue.status
     self.author = User.current
diff --git a/test/unit/issue_test.rb b/test/unit/issue_test.rb
index 318f311..7b44e70 100644
--- a/test/unit/issue_test.rb
+++ b/test/unit/issue_test.rb
@@ -697,7 +697,7 @@ class IssueTest < ActiveSupport::TestCase
     user = User.find(2)
     group = Group.generate!
     group.users << user
- 
+
     issue = Issue.generate!(:author_id => 1, :assigned_to => group)
     assert_include 4, issue.new_statuses_allowed_to(user).map(&:id)
   end
@@ -1268,6 +1268,16 @@ class IssueTest < ActiveSupport::TestCase
     end
   end
 
+  def test_copy_should_clear_closed_on
+    copied_open = Issue.find(8).copy(:status_id => 1)
+    assert copied_open.save
+    assert_nil copied_open.closed_on
+
+    copied_closed = Issue.find(8).copy
+    assert copied_closed.save
+    assert_not_nil copied_closed.closed_on
+  end
+
   def test_should_not_call_after_project_change_on_creation
     issue = Issue.new(:project_id => 1, :tracker_id => 1, :status_id => 1,
                       :subject => 'Test', :author_id => 1)