diff --git a/tools/.gitattributes b/tools/.gitattributes
new file mode 100644
index 0000000..0196216
--- /dev/null
+++ b/tools/.gitattributes
@@ -0,0 +1 @@
+create_version_h.sh export-subst
diff --git a/tools/create_version_h.sh b/tools/create_version_h.sh
index 83b33d6..548715e 100755
--- a/tools/create_version_h.sh
+++ b/tools/create_version_h.sh
@@ -6,7 +6,12 @@ H_FILE=$1

 VERSION_H_NEEDS_UPDATE=1

-NEW_VERSION=`git describe --tags HEAD | sed 's,^release-,,;s,-,+,;s,-,~,;'`
+NEW_VERSION=`git describe --tags --dirty | sed 's,^release-,,;s,-,+,;s,-,~,;'`
+
+# if we are not in a git checkout, NEW_VERSION is empty
+if [ -z "${NEW_VERSION}" ]; then
+   NEW_VERSION="a $NEW_VERSION a archive-$Format:%H"
+fi

 # version.h exists => check if it containts the up-to-date version
 if [ -f ${H_FILE} ]; then
@@ -17,5 +22,5 @@ if [ -f ${H_FILE} ]; then
 fi

 if [ $VERSION_H_NEEDS_UPDATE -eq 1 ]; then
-  echo "#define PACKAGE_VERSION \"${NEW_VERSION}\"" > ${H_FILE}
+  echo "#define PACKAGE_VERSION \"${NEW_VERSION}\"" >> ${H_FILE}
 fi