diff --git a/npm2git.sh b/npm2git.sh
index 54b9f87..97e5ad9 100755
--- a/npm2git.sh
+++ b/npm2git.sh
@@ -1,36 +1,39 @@
-# get ready
+#!/bin/sh
+
+# git ready
 set -e
 cd "$(git rev-parse --show-toplevel)"
 ORIG_HEAD="$(git symbolic-ref HEAD)"
 ORIG_COMMIT="$(git rev-parse HEAD)"
 
 # extract version from package.json, and remove scripts.prepare
-cp package.json package.json_orig
+cp package.json package.json.bak
 PKG_VERSION="$(node -e '
-	const pkg = require("./package.json");
+	const fs = require("fs");
+	const pkg = JSON.parse(fs.readFileSync("package.json"));
 	pkg.scripts && delete pkg.scripts.prepare;
-	require("fs").writeFileSync("package.json", JSON.stringify(pkg));
+	fs.writeFileSync("package.json", JSON.stringify(pkg));
 	console.log(pkg.version);
 ')"
 
 # create new temporary branch
-TEMP_BRANCH="NPM2GIT_${PKG_VERSION}_$(date +'%Y%m%d%H%M%S')"
-git checkout --orphan="${TEMP_BRANCH}"
+TEMP_BRANCH="NPM2GIT-$PKG_VERSION-$(date +%Y%m%d%H%M%S)"
+git checkout --orphan="$TEMP_BRANCH"
 git rm --cached -rf .
 
 # commit the files that should be included in the published package
 PKG_TAR="$(npm pack | tail -n 1)"
-tar tf "${PKG_TAR}" | cut -c 9- | xargs -d '\n' git add -f
-git commit -m "v${PKG_VERSION} @ ${ORIG_COMMIT}"
+tar tf "$PKG_TAR" | cut -c 9- | xargs -d '\n' git add -f
+git commit -m "v$PKG_VERSION @ $ORIG_COMMIT"
 
 # return to original state
-rm "${PKG_TAR}"
-mv -f package.json_orig package.json
-git symbolic-ref HEAD "${ORIG_HEAD}"
+rm "$PKG_TAR"
+mv -f package.json.bak package.json
+git symbolic-ref HEAD "$ORIG_HEAD"
 git reset
 
 # tag commit
-git tag "v${PKG_VERSION}" "${TEMP_BRANCH}" -am "v${PKG_VERSION} @ ${ORIG_COMMIT}"
+git tag "v$PKG_VERSION" "$TEMP_BRANCH" -am "v$PKG_VERSION @ $ORIG_COMMIT"
 
 # delete temporary branch
-git branch -D "${TEMP_BRANCH}"
+git branch -D "$TEMP_BRANCH"