diff --git a/lcache.install b/lcache.install
index 701a68e..1e1d6e2 100644
--- a/lcache.install
+++ b/lcache.install
@@ -70,9 +70,8 @@ function lcache_schema() {
         'description' => 'Cache tag.',
         'type' => 'varchar',
         'length' => 128,
-        'not null' => FALSE,
+        'not null' => TRUE,
         'binary' => TRUE,
-        'default' => NULL,
       ),
       'event_id' => array(
         'description' => 'The event_id associated with the cache entry.',