diff --git a/release.sh b/release.sh
index 3d4b1211ad3c6bb439807054e715eed698a94877..b354fe415d68f2ed00fe6d6ed63a417932dc0a5b 100755
--- a/release.sh
+++ b/release.sh
@@ -4,7 +4,7 @@
 current=`grep -P "__version__     = \'\d+.\d+.\d+(\w*)\'" duniterpy/__init__.py | grep -oP "\d+.\d+.\d+(\w*)"`
 echo "Current version: $current"
 
-if [[ $1 =~ ^[0-9]+.[0-9]+.[0-9]+[0-9a-z]+$ ]]; then
+if [[ $1 =~ ^[0-9]+.[0-9]+.[0-9]+[0-9a-z]*$ ]]; then
   sed -i "s/__version__     = '$current'/__version__     = '$1'/g" duniterpy/__init__.py
   git commit duniterpy/__init__.py -m "$1"
   git tag "$1" -a -m "$1"