diff --git a/blockcache_alter.install b/blockcache_alter.install
index ecb410e..e2d0a53 100644
--- a/blockcache_alter.install
+++ b/blockcache_alter.install
@@ -29,7 +29,7 @@ function blockcache_alter_schema() {
       ),
       'delta' => array(
         'type' => 'varchar',
-        'length' => 32,
+        'length' => 64,
         'not null' => TRUE,
         'default' => '0',
         'description' => 'Unique ID for block within a module.',