diff --git a/extlink.install b/extlink.install
index b1e083b..e04b0b5 100644
--- a/extlink.install
+++ b/extlink.install
@@ -7,3 +7,11 @@ function extlink_install() {
   // Weight needs to be 1 for compatibility with SpamSpan.
   db_query("UPDATE {system} SET weight = 1 WHERE name = 'extlink'");
 }
+
+/**
+ * Implementation of hook_uninstall().
+ */
+function extlink_uninstall() {
+  db_query("DELETE FROM {variable} WHERE name LIKE 'extlink_%'");
+  cache()->deleteTags(array('variables' => TRUE));
+}