diff --git a/clean_files.txt b/clean_files.txt
index ba2e7704..60717004 100644
--- a/clean_files.txt
+++ b/clean_files.txt
@@ -17,6 +17,7 @@
 # root directories
 #
 aliases/
+custom/
 docs/
 hooks/
 lib/
diff --git a/custom/example.bash b/custom/example.bash
index 3e66ba80..05653f1f 100644
--- a/custom/example.bash
+++ b/custom/example.bash
@@ -1,4 +1,4 @@
-#!/usr/bin/env bash
+# shellcheck shell=bash
 #
 # This is an example file. Don't use this for your custom scripts. Instead, create another file within the
 # custom directory.