diff --git a/modules/block/block.install b/modules/block/block.install
index b2ab477..275486a 100644
--- a/modules/block/block.install
+++ b/modules/block/block.install
@@ -137,7 +137,7 @@ function block_schema() {
         'type' => 'serial',
         'unsigned' => TRUE,
         'not null' => TRUE,
-        'description' => "The block's {block}.bid.",
+        'description' => "The block's {block}.delta.",
       ),
       'body' => array(
         'type' => 'text',
@@ -464,5 +464,17 @@ function block_update_7008() {
 }
 
 /**
+ * Change the description of {block_custom}.bid.
+ */
+function block_update_7009() {
+  db_change_field('block_custom', 'bid', 'bid', array(
+    'type' => 'serial',
+    'unsigned' => TRUE,
+    'not null' => TRUE,
+    'description' => "The block's {block}.delta.",
+  ));
+}
+
+/**
  * @} End of "addtogroup updates-6.x-to-7.x"
  */