diff --git a/scripts/prepare b/scripts/prepare
index 0186affcbb4d3203d76d6bd5eb06553173bec124..7615c98e6edf7f6ffb9bdf5dda2681bb282a8254 100755
--- a/scripts/prepare
+++ b/scripts/prepare
@@ -1,7 +1,7 @@
-#!/bin/bash
+#!/bin/sh
 
 PROJDIR="$(cd "$(dirname "${0}")/../" && pwd)"
 
-if [[ ! -d "${PROJDIR}/lib/qtil" ]]; then
+if [ ! -d "${PROJDIR}/lib/qtil" ]; then
     git clone https://github.com/akiraohgaki/qtil.git -b release-0.4.0 --single-branch --depth=1 "${PROJDIR}/lib/qtil"
 fi