diff --git a/blockcache_alter.install b/blockcache_alter.install
index 106be43..050d2b0 100644
--- a/blockcache_alter.install
+++ b/blockcache_alter.install
@@ -49,6 +49,15 @@ function blockcache_alter_schema() {
 }
 
 /**
+ * Implements hook_uninstall().
+ */
+function blockcache_alter_uninstall() {
+  variable_del('bca_corepatch');
+  variable_del('bca_debug');
+  variable_del('bca_user1');
+}
+
+/**
  * Add the "bid" column to {blockcache_alter} and backfill block IDs.
  */
 function blockcache_alter_update_7000() {