Index: lib/redmine/plugin.rb
===================================================================
--- lib/redmine/plugin.rb	(revision 17430)
+++ lib/redmine/plugin.rb	(working copy)
@@ -479,7 +479,7 @@
         def migrate_plugin(plugin, version)
           self.current_plugin = plugin
           return if current_version(plugin) == version
-          migrate(plugin.migration_directory, version)
+          ActiveRecord::MigrationContext.new(plugin.migration_directory).migrate(version)
         end
 
         def current_version(plugin=current_plugin)
Index: test/unit/lib/redmine/plugin_test.rb
===================================================================
--- test/unit/lib/redmine/plugin_test.rb	(revision 17430)
+++ test/unit/lib/redmine/plugin_test.rb	(working copy)
@@ -183,4 +183,13 @@
     Rails.logger.expects(:warn)
     @klass.register(:bar) { settings :partial => 'foo/settings' }
   end
+
+  def test_migrate_redmine_plugin
+    @klass.register :foo do
+      name 'Foo plugin'
+      version '0.0.1'
+    end
+
+    assert Redmine::Plugin.migrate('foo')
+  end
 end