diff --git a/lib/friendly_id/scoped.rb b/lib/friendly_id/scoped.rb
index 92b3dd7e2..4bb072168 100644
--- a/lib/friendly_id/scoped.rb
+++ b/lib/friendly_id/scoped.rb
@@ -127,13 +127,13 @@ def scope_for_slug_generator
         relation = relation.where(column => send(column))
       end
       if changed.include?(friendly_id_config.slug_column)
-        column = self.class.quoted_table_name + '.' + self.class.quoted_primary_key
-        relation = relation.where("#{column} <> ?", send(self.class.primary_key))
+        primary_key_name = self.class.primary_key
+        relation = relation.where.not(primary_key_name => send(primary_key_name))
       end
       relation
     end
     private :scope_for_slug_generator
-    
+
     def slug_generator
       friendly_id_config.slug_generator_class.new(scope_for_slug_generator)
     end
diff --git a/lib/friendly_id/slugged.rb b/lib/friendly_id/slugged.rb
index e8b7186dc..63d3017a1 100644
--- a/lib/friendly_id/slugged.rb
+++ b/lib/friendly_id/slugged.rb
@@ -302,8 +302,8 @@ def scope_for_slug_generator
       scope = scope.friendly unless friendly_id_config.uses? :finders
 
       if changed.include?(friendly_id_config.slug_column)
-        column = self.class.quoted_table_name + '.' + self.class.quoted_primary_key
-        scope = scope.where("#{column} <> ?", send(self.class.primary_key))
+        primary_key_name = self.class.primary_key
+        scope = scope.where.not(primary_key_name => send(primary_key_name))
       end
       scope
     end
diff --git a/test/scoped_test.rb b/test/scoped_test.rb
index 5d92d4bad..57f867ba0 100644
--- a/test/scoped_test.rb
+++ b/test/scoped_test.rb
@@ -10,6 +10,10 @@ class Novel < ActiveRecord::Base
   belongs_to :novelist
   belongs_to :publisher
   friendly_id :name, :use => :scoped, :scope => [:publisher, :novelist]
+
+  def should_generate_new_friendly_id?
+    new_record? || super
+  end
 end
 
 class Publisher < ActiveRecord::Base
@@ -54,6 +58,36 @@ def model_class
     end
   end
 
+  test "should not allow duplicate slugs inside scope after regeneration for persisted record" do
+    with_instance_of Novelist do |novelist|
+      novel1 = Novel.create! :name => "a", :novelist => novelist
+      novel2 = Novel.new :name => "a", :novelist => novelist
+      novel2.save!
+
+      novel2.send(:set_slug)
+      first_generated_friendly_id = novel2.friendly_id
+      novel2.send(:set_slug)
+      second_generated_friendly_id = novel2.friendly_id
+
+      assert novel1.friendly_id != novel2.friendly_id
+    end
+  end
+
+  test "should not allow duplicate slugs inside scope after regeneration for new record" do
+    with_instance_of Novelist do |novelist|
+      novel1 = Novel.create! :name => "a", :novelist => novelist
+      novel2 = Novel.new :name => "a", :novelist => novelist
+
+      novel2.send(:set_slug)
+      first_generated_friendly_id = novel2.friendly_id
+      novel2.send(:set_slug)
+      second_generated_friendly_id = novel2.friendly_id
+      novel2.save!
+
+      assert novel1.friendly_id != novel2.friendly_id
+    end
+  end
+
   test "should apply scope with multiple columns" do
     transaction do
       novelist = Novelist.create! :name => "a"
diff --git a/test/slugged_test.rb b/test/slugged_test.rb
index 09cdfd0aa..ad50ff17e 100644
--- a/test/slugged_test.rb
+++ b/test/slugged_test.rb
@@ -141,6 +141,35 @@ def model_class
     end
   end
 
+  test "should not allow duplicate slugs after regeneration for persisted record" do
+    transaction do
+      model1 = model_class.create! :name => "a"
+      model2 = model_class.new :name => "a"
+      model2.save!
+
+      model2.send(:set_slug)
+      first_generated_friendly_id = model2.friendly_id
+      model2.send(:set_slug)
+      second_generated_friendly_id = model2.friendly_id
+
+      assert model1.friendly_id != model2.friendly_id
+    end
+  end
+
+  test "should not allow duplicate slugs after regeneration for new record" do
+    transaction do
+      model1 = model_class.create! :name => "a"
+      model2 = model_class.new :name => "a"
+
+      model2.send(:set_slug)
+      first_generated_friendly_id = model2.friendly_id
+      model2.send(:set_slug)
+      second_generated_friendly_id = model2.friendly_id
+
+      assert model1.friendly_id != model2.friendly_id
+    end
+  end
+
 end
 
 class SlugSeparatorTest < MiniTest::Unit::TestCase
@@ -220,7 +249,7 @@ class MenuItem < ActiveRecord::Base
     friendly_id :name, :use => :slugged
     before_create :init_primary_key
 
-    def self.primary_key 
+    def self.primary_key
       "string_key"
     end