diff --git a/wtfitpoc b/wtfitpoc
index 1fc1e19..b3d7120 100755
--- a/wtfitpoc
+++ b/wtfitpoc
@@ -1,4 +1,4 @@
-#!/usr/bin/env bash
+#!/bin/sh
 # overlay.sh <overlay-image>
 
 set -e