diff --git casetracker.views.inc casetracker.views.inc
index 3b184a4..07b1380 100644
--- casetracker.views.inc
+++ casetracker.views.inc
@@ -34,6 +34,10 @@ function casetracker_views_data_casetracker_case() {
       'handler' => 'casetracker_views_handler_filter_project_options',
       'help' => t('Filter Case Tracker cases by their project.'),
     ),
+    'argument' => array(
+      'handler' => 'views_handler_argument_numeric',
+      'help' => t('Filter Case Tracker cases by their project.'),
+    ),
     'relationship' => array(
       'handler' => 'views_handler_relationship',
       'base' => 'node',