diff --git a/.github/workflows/python-publish.yaml b/.github/workflows/python-publish.yaml
index 2aa82b3..0d058a4 100644
--- a/.github/workflows/python-publish.yaml
+++ b/.github/workflows/python-publish.yaml
@@ -33,6 +33,7 @@ jobs:
     - name: Update package version
       run: |
         VERSION=${{ github.event.release.tag_name }}
+        sed -i 's/__version__ = ".*"/__version__ = "'${VERSION}'"/' _version.py
         sed -i "s/version='.*'/version='${VERSION}'/" setup.py
     - name: Build package
       run: python -m build
diff --git a/datastew/__init__.py b/datastew/__init__.py
index c408349..8984012 100644
--- a/datastew/__init__.py
+++ b/datastew/__init__.py
@@ -1,6 +1,7 @@
 from .visualisation import *
 from .mapping import *
 from .embedding import *
+from ._version import __version__
 
 # Importing submodules to expose their attributes if needed
 from .process import mapping, parsing
diff --git a/datastew/_version.py b/datastew/_version.py
new file mode 100644
index 0000000..e5038cf
--- /dev/null
+++ b/datastew/_version.py
@@ -0,0 +1 @@
+__version__ = "0.4.0" # will be substituted in publish workflow
diff --git a/setup.py b/setup.py
index 42d5ff0..b4ef56f 100644
--- a/setup.py
+++ b/setup.py
@@ -1,5 +1,6 @@
 import io
 import os
+
 from setuptools import setup, find_packages
 
 DESCRIPTION = 'Intelligent data steward toolbox using Large Language Model embeddings for automated Data-Harmonization.'
@@ -14,7 +15,7 @@
 
 setup(
     name='datastew',
-    version='0.1.0',  # will be substituted in publish workflow
+    version='0.4.0', # will be substituted in publish workflow
     packages=find_packages(),  # This will automatically find all packages and sub-packages
     url='https://github.com/SCAI-BIO/datastew',
     license='Apache-2.0 license',
diff --git a/tests/test_version.py b/tests/test_version.py
new file mode 100644
index 0000000..2b6bc6b
--- /dev/null
+++ b/tests/test_version.py
@@ -0,0 +1,15 @@
+import re
+from unittest import TestCase
+import datastew
+
+
+class Test(TestCase):
+    def test_canonical_version(self):
+        version = datastew.__version__
+        return (
+            re.match(
+                r"^([1-9][0-9]*!)?(0|[1-9][0-9]*)(\.(0|[1-9][0-9]*))*((a|b|rc)(0|[1-9][0-9]*))?(\.post(0|[1-9][0-9]*))?(\.dev(0|[1-9][0-9]*))?$",
+                version,
+            )
+            is not None
+        )