diff --git a/configure.ac b/configure.ac
index e448619..8dbbcee 100644
--- a/configure.ac
+++ b/configure.ac
@@ -4,7 +4,6 @@ AC_INIT([glorytun],
         [https://github.com/angt/glorytun/issues],
         [glorytun],
         [https://github.com/angt/glorytun])
-AC_DEFINE_UNQUOTED([VERSION_MAJOR], [m4_esyscmd([./version.sh major])])
 AC_CONFIG_SRCDIR([src/common.h])
 AC_CONFIG_AUX_DIR([build-aux])
 AC_CONFIG_MACRO_DIR([m4])
diff --git a/version.sh b/version.sh
index 2951cb2..2b0ea3f 100755
--- a/version.sh
+++ b/version.sh
@@ -1,13 +1,12 @@
 #!/bin/sh
 
-[ -z "${VERSION}" ] && VERSION=`git describe --tags --match='v[0-9].*' 2>/dev/null` \
-                    && VERSION=${VERSION#v}
+[ -z "${VERSION}" ] && VERSION="$(git describe --tags --match='v[0-9].*' 2>/dev/null)" \
+                    && VERSION="${VERSION#v}"
 
-[ -z "${VERSION}" ] && VERSION=`cat VERSION 2>/dev/null`
+[ -z "${VERSION}" ] && VERSION="$(git rev-parse HEAD 2>/dev/null)"
 
-[ -z "${VERSION}" ] && VERSION=0.0.0
+[ -z "${VERSION}" ] && VERSION="$(cat VERSION 2>/dev/null)"
 
-[ "$1" = "major"  ] && printf ${VERSION%%.*} \
-                    && exit 0
+[ -z "${VERSION}" ] && VERSION="0.0.0"
 
-printf ${VERSION} | tee VERSION
+printf "%s" "${VERSION}" | tee VERSION