diff --git a/lib/kaminari/models/data_mapper_extension.rb b/lib/kaminari/models/data_mapper_extension.rb
index 4778da7..396dba8 100644
--- a/lib/kaminari/models/data_mapper_extension.rb
+++ b/lib/kaminari/models/data_mapper_extension.rb
@@ -5,8 +5,10 @@ module Kaminari
     module Paginatable
       class_eval <<-RUBY, __FILE__, __LINE__ + 1
         def #{Kaminari.config.page_method_name}(num = 1)
+          model = self
+          model = self.model if self.is_a? DataMapper::Collection
           num = [num.to_i, 1].max - 1
-          all(:limit => default_per_page, :offset => default_per_page * num).extend Paginating
+          all(:limit => model.default_per_page, :offset => model.default_per_page * num).extend Paginating
         end
       RUBY
     end
diff --git a/spec/models/active_record/active_record_relation_methods_spec.rb b/spec/models/active_record/active_record_relation_methods_spec.rb
index 548d7c9..fa45fcc 100644
--- a/spec/models/active_record/active_record_relation_methods_spec.rb
+++ b/spec/models/active_record/active_record_relation_methods_spec.rb
@@ -38,7 +38,7 @@ if defined? ActiveRecord
       end
 
       context "when total_count receives options" do
-        it "should return a distinct total count for rails ~> 4.0.0" do
+        it "should return a distinct total count for rails < 4.1" do
           if ActiveRecord::VERSION::STRING < "4.1.0"
             User.page(1).total_count(:name, :distinct => true).should == 4
           end
@@ -52,7 +52,7 @@ if defined? ActiveRecord
       end
 
       context "when count receives options" do
-        it "should return a distinct set by column for rails ~> 4.0.0" do
+        it "should return a distinct set by column for rails < 4.1" do
           if ActiveRecord::VERSION::STRING < "4.1.0"
             User.page(1).count(:name, :distinct => true).should == 4
           end
diff --git a/spec/models/data_mapper/data_mapper_spec.rb b/spec/models/data_mapper/data_mapper_spec.rb
index aedcc68..f81b462 100644
--- a/spec/models/data_mapper/data_mapper_spec.rb
+++ b/spec/models/data_mapper/data_mapper_spec.rb
@@ -17,13 +17,13 @@ if defined? DataMapper
 
     describe 'Model' do
       subject { User }
-      its(:current_page) { should == 1 }
       it { User.all.count.should == 100 }
       it { User.page(1).length.should == 25 }
       it {
         User.paginates_per(5)
         User.page(1).length.should == 5
         User.all.page(1).length.should == 5
+        User.paginates_per(nil) # reset to default
       }
     end
 
diff --git a/spec/support/database_cleaner.rb b/spec/support/database_cleaner.rb
index c75f500..05a5c13 100644
--- a/spec/support/database_cleaner.rb
+++ b/spec/support/database_cleaner.rb
@@ -5,8 +5,6 @@ DatabaseCleaner[:mongo_mapper].strategy = :truncation if defined? MongoMapper
 
 RSpec.configure do |config|
   config.before :suite do
-    #DatabaseCleaner.clean_with :truncation
-
     DatabaseCleaner.clean_with :truncation if defined? ActiveRecord
     DatabaseCleaner.clean_with :truncation if defined? DataMapper
     DatabaseCleaner.clean_with :truncation if defined? Mongoid