diff --git a/activerecord/lib/active_record/named_scope.rb b/activerecord/lib/active_record/named_scope.rb
index 60ff4b5..f90afbf 100644
--- a/activerecord/lib/active_record/named_scope.rb
+++ b/activerecord/lib/active_record/named_scope.rb
@@ -101,7 +101,7 @@ module ActiveRecord
     
     class Scope
       attr_reader :proxy_scope, :proxy_options, :current_scoped_methods_when_defined
-      NON_DELEGATE_METHODS = %w(nil? send object_id class extend find size count sum average maximum minimum paginate first last empty? any? respond_to?).to_set
+      NON_DELEGATE_METHODS = %w(nil? send object_id class extend find size count sum average maximum minimum paginate first last merge empty? any? respond_to?).to_set
       [].methods.each do |m|
         unless m =~ /^__/ || NON_DELEGATE_METHODS.include?(m.to_s)
           delegate m, :to => :proxy_found
@@ -159,6 +159,10 @@ module ActiveRecord
         end
       end
 
+      def merge(other)
+        Scope.new(self, other.proxy_options)
+      end
+
       protected
       def proxy_found
         @found || load_found
diff --git a/activerecord/test/cases/named_scope_test.rb b/activerecord/test/cases/named_scope_test.rb
index 6149681..cb5e10b 100644
--- a/activerecord/test/cases/named_scope_test.rb
+++ b/activerecord/test/cases/named_scope_test.rb
@@ -90,6 +90,18 @@ class NamedScopeTest < ActiveRecord::TestCase
     assert_equal approved & replied, Topic.approved.replied
   end
 
+  def test_scopes_are_mergeable
+    approved_scope = Topic.approved
+    replied_scope = Topic.replied
+
+    assert_equal (approved = Topic.find(:all, :conditions => {:approved => true})), approved_scope
+    assert_equal (replied = Topic.find(:all, :conditions => 'replies_count > 0')), replied_scope
+    assert !(approved == replied)
+    assert !(approved & replied).empty?
+
+    assert_equal approved & replied, approved_scope.merge(replied_scope)
+  end
+
   def test_procedural_scopes
     topics_written_before_the_third = Topic.find(:all, :conditions => ['written_on < ?', topics(:third).written_on])
     topics_written_before_the_second = Topic.find(:all, :conditions => ['written_on < ?', topics(:second).written_on])