diff --git a/app/controllers/issues_controller.rb b/app/controllers/issues_controller.rb
index 23d3992f1..8ba4148c5 100644
--- a/app/controllers/issues_controller.rb
+++ b/app/controllers/issues_controller.rb
@@ -515,6 +515,7 @@ class IssuesController < ApplicationController
       attrs.delete(:fixed_version_id)
     end
     @issue.safe_attributes = attrs
+    @issue.watcher_user_ids = [] if params[:issue] && params[:issue][:watcher_user_ids].blank?
 
     if @issue.project
       @issue.tracker ||= @issue.allowed_target_trackers.first
diff --git a/test/functional/issues_controller_test.rb b/test/functional/issues_controller_test.rb
index 34d353263..0ed940e48 100644
--- a/test/functional/issues_controller_test.rb
+++ b/test/functional/issues_controller_test.rb
@@ -4207,6 +4207,45 @@ class IssuesControllerTest < Redmine::ControllerTest
     assert_equal 1, issue.project_id
   end
 
+  def test_create_as_copy_with_watcher_user_ids_should_copy_watchers
+    @request.session[:user_id] = 2
+    copied = Issue.generate!
+    copied.add_watcher User.find(2)
+    copied.add_watcher User.find(3)
+
+    assert_difference 'Issue.count' do
+      post :create, :params => {
+          :project_id => 1,
+          :copy_from => copied.id,
+          :issue => {
+            :subject => 'Copy cleared watchers',
+            :watcher_user_ids => [3]
+          }
+        }
+    end
+    issue = Issue.order('id DESC').first
+    assert_equal [3], issue.watcher_user_ids
+  end
+
+  def test_create_as_copy_without_watcher_user_ids_should_not_copy_watchers
+    @request.session[:user_id] = 2
+    copied = Issue.generate!
+    copied.add_watcher User.find(2)
+    copied.add_watcher User.find(3)
+
+    assert_difference 'Issue.count' do
+      post :create, :params => {
+          :project_id => 1,
+          :copy_from => copied.id,
+          :issue => {
+            :subject => 'Copy cleared watchers'
+          }
+        }
+    end
+    issue = Issue.order('id DESC').first
+    assert_equal [], issue.watcher_user_ids
+  end
+
   def test_get_edit
     @request.session[:user_id] = 2
     get :edit, :params => {