--- category.install	2007-01-05 16:31:15.000000000 +0100
+++ category.install	2009-07-18 17:59:31.000000000 +0200
@@ -267,4 +267,24 @@
   variable_set('category_base_nodetypes', $base_nodetypes);
 
   return $ret;
 }
+
+
+/**
+ * Implementation of hook_uninstall().
+ */
+function category_uninstall() {
+  db_query('DROP TABLE {category}');
+  db_query('DROP TABLE {category_hierarchy}');
+  db_query('DROP TABLE {category_node}');
+  db_query('DROP TABLE {category_relation}');
+  db_query('DROP TABLE {category_synonym}');
+  db_query('DROP TABLE {category_cont}');
+  db_query('DROP TABLE {category_cont_distant}');
+  db_query('DROP TABLE {category_cont_node_types}');
+
+  variable_del('category_allow_nodetypes');
+  variable_del('category_base_nodetypes');
+  variable_del('category_distant_containers');
+
+}