diff --git a/app/controllers/moderator/post/posts_controller.rb b/app/controllers/moderator/post/posts_controller.rb
index 0a410cfb0..e8367e564 100644
--- a/app/controllers/moderator/post/posts_controller.rb
+++ b/app/controllers/moderator/post/posts_controller.rb
@@ -12,7 +12,7 @@ module Moderator
       def delete
         @post = ::Post.find(params[:id])
         if params[:commit] == "Delete"
-          @post.flag!(params[:reason])
+          @post.flag!(params[:reason], :is_deletion => true)
           @post.delete!(:reason => params[:reason], :move_favorites => params[:move_favorites].present?)
         end
         redirect_to(post_path(@post))
diff --git a/app/models/post.rb b/app/models/post.rb
index 492a6133a..6b2df0d28 100644
--- a/app/models/post.rb
+++ b/app/models/post.rb
@@ -218,12 +218,12 @@ class Post < ActiveRecord::Base
       !is_status_locked? && (is_pending? || is_flagged? || is_deleted?) && approver_id != CurrentUser.id
     end
 
-    def flag!(reason)
+    def flag!(reason, options = {})
       if is_status_locked?
         raise PostFlag::Error.new("Post is locked and cannot be flagged")
       end
 
-      flag = flags.create(:reason => reason, :is_resolved => false)
+      flag = flags.create(:reason => reason, :is_resolved => false, :is_deletion => options[:is_deletion])
 
       if flag.errors.any?
         raise PostFlag::Error.new(flag.errors.full_messages.join("; "))
diff --git a/app/models/post_flag.rb b/app/models/post_flag.rb
index 8d77e044d..fe5692497 100644
--- a/app/models/post_flag.rb
+++ b/app/models/post_flag.rb
@@ -7,9 +7,10 @@ class PostFlag < ActiveRecord::Base
   validate :validate_creator_is_not_limited
   validate :validate_post_is_active
   before_validation :initialize_creator, :on => :create
-  validates_uniqueness_of :creator_id, :scope => :post_id, :message => "have already flagged this post"
+  validates_uniqueness_of :creator_id, :scope => :post_id, :on => :create, :unless => :is_deletion, :message => "have already flagged this post"
   before_save :update_post
-  attr_accessible :post, :post_id, :reason, :is_resolved
+  attr_accessible :post, :post_id, :reason, :is_resolved, :is_deletion
+  attr_accessor :is_deletion
 
   module SearchMethods
     def resolved
diff --git a/test/functional/moderator/post/posts_controller_test.rb b/test/functional/moderator/post/posts_controller_test.rb
index 1eb02ea51..6357740d2 100644
--- a/test/functional/moderator/post/posts_controller_test.rb
+++ b/test/functional/moderator/post/posts_controller_test.rb
@@ -20,6 +20,13 @@ module Moderator
             @post.reload
             assert(@post.is_deleted?)
           end
+
+          should "work even if the deleter has flagged the post previously" do
+            PostFlag.create(:post => @post, :reason => "aaa", :is_resolved => false)
+            post :delete, {:id => @post.id, :reason => "xxx", :format => "js", :commit => "Delete"}, {:user_id => @admin.id}
+            @post.reload
+            assert(@post.is_deleted?)
+          end
         end
 
         context "undelete action" do