diff --git a/vendor/plugins/engines/boot.rb b/vendor/plugins/engines/boot.rb
index 1c55e2139..7dd90d17a 100644
--- a/vendor/plugins/engines/boot.rb
+++ b/vendor/plugins/engines/boot.rb
@@ -10,7 +10,7 @@ require File.join(File.dirname(__FILE__), 'lib/engines')
 # initialize Rails::Configuration with our own default values to spare users 
 # some hassle with the installation and keep the environment cleaner
 
-{ :default_plugin_locators => [Engines::Plugin::FileSystemLocator],
+{ :default_plugin_locators => (defined?(Gem) ? [Rails::Plugin::GemLocator] : []).push(Engines::Plugin::FileSystemLocator),
   :default_plugin_loader => Engines::Plugin::Loader,
   :default_plugins => [:engines, :all] }.each do |name, default|    
   Rails::Configuration.send(:define_method, name) { default }
diff --git a/vendor/plugins/engines/generators/plugin_migration/plugin_migration_generator.rb b/vendor/plugins/engines/generators/plugin_migration/plugin_migration_generator.rb
index 5944ae231..d6ecbd489 100644
--- a/vendor/plugins/engines/generators/plugin_migration/plugin_migration_generator.rb
+++ b/vendor/plugins/engines/generators/plugin_migration/plugin_migration_generator.rb
@@ -48,7 +48,7 @@ class PluginMigrationGenerator < Rails::Generator::Base
         end
       end
       
-      @plugins_to_migrate.reject! { |p| p.latest_migration.nil? }
+      @plugins_to_migrate.reject! { |p| !p.respond_to?(:latest_migration) || p.latest_migration.nil? }
       
       # Then find the current versions from the database    
       @current_versions = {}