diff --git a/generate-version.sh b/generate-version.sh
index 014d1b9..388ce7f 100755
--- a/generate-version.sh
+++ b/generate-version.sh
@@ -1,4 +1,4 @@
-#!/usr/bin/bash
+#!/bin/sh
 
 set -e
 
@@ -10,16 +10,22 @@ out_file=${3}
 # echo "source directory: ${src_dir}"
 # echo "output file:      ${out_file}"
 
-if [[ $(command -v git) ]]; then
-    new_version="$(git describe --always --tags) ($(env LC_TIME=C date "+%b %d %Y"), branch '$(git rev-parse --abbrev-ref HEAD)')"
+if command -v git > /dev/null; then
+    workdir=$(pwd)
+    cd "${src_dir}"
+    git_version=$(git describe --always --tags)
+    git_branch=$(git rev-parse --abbrev-ref HEAD)
+    cd "${workdir}"
+
+    new_version="${git_version} ($(env LC_TIME=C date "+%b %d %Y"), branch '${git_branch}')"
 else
     new_version="${default_version}"
 fi
 
 new_version="#define YAMBAR_VERSION \"${new_version}\""
 
-if [[ -f "${out_file}" ]]; then
-    old_version=$(<"${out_file}")
+if [ -f "${out_file}" ]; then
+    old_version=$(cat "${out_file}")
 else
     old_version=""
 fi
@@ -27,6 +33,6 @@ fi
 # echo "old version: ${old_version}"
 # echo "new version: ${new_version}"
 
-if [[ "${old_version}" != "${new_version}" ]]; then
+if [ "${old_version}" != "${new_version}" ]; then
     echo "${new_version}" > "${out_file}"
 fi