diff --git a/PKG-INFO b/PKG-INFO
index 8cf842c..71abcc9 100644
--- a/PKG-INFO
+++ b/PKG-INFO
@@ -1,10 +1,10 @@
 Metadata-Version: 1.0
 Name: swh.model
-Version: 0.0.18
+Version: 0.0.19
 Summary: Software Heritage data model
 Home-page: https://forge.softwareheritage.org/diffusion/DMOD/
 Author: Software Heritage developers
 Author-email: swh-devel@inria.fr
 License: UNKNOWN
 Description: UNKNOWN
 Platform: UNKNOWN
diff --git a/setup.py b/setup.py
index 8d2e843..232f3bc 100644
--- a/setup.py
+++ b/setup.py
@@ -1,40 +1,37 @@
 import hashlib
 
-from setuptools import setup
+from setuptools import setup, find_packages
 
 
 def parse_requirements():
     requirements = []
     for reqf in ('requirements.txt', 'requirements-swh.txt'):
         with open(reqf) as f:
             for line in f.readlines():
                 line = line.strip()
                 if not line or line.startswith('#'):
                     continue
                 requirements.append(line)
     return requirements
 
 
 extra_requirements = []
 
 
 pyblake2_hashes = {'blake2s256', 'blake2b512'}
 if pyblake2_hashes - set(hashlib.algorithms_available):
     extra_requirements.append('pyblake2')
 
 setup(
     name='swh.model',
     description='Software Heritage data model',
     author='Software Heritage developers',
     author_email='swh-devel@inria.fr',
     url='https://forge.softwareheritage.org/diffusion/DMOD/',
-    packages=[
-        'swh.model', 'swh.model.fields',
-        'swh.model.tests', 'swh.model.tests.fields',
-    ],  # packages's modules
+    packages=find_packages(),  # packages's modules
     scripts=[],   # scripts to package
     install_requires=parse_requirements() + extra_requirements,
     setup_requires=['vcversioner'],
     vcversioner={},
     include_package_data=True,
 )
diff --git a/swh.model.egg-info/PKG-INFO b/swh.model.egg-info/PKG-INFO
index 8cf842c..71abcc9 100644
--- a/swh.model.egg-info/PKG-INFO
+++ b/swh.model.egg-info/PKG-INFO
@@ -1,10 +1,10 @@
 Metadata-Version: 1.0
 Name: swh.model
-Version: 0.0.18
+Version: 0.0.19
 Summary: Software Heritage data model
 Home-page: https://forge.softwareheritage.org/diffusion/DMOD/
 Author: Software Heritage developers
 Author-email: swh-devel@inria.fr
 License: UNKNOWN
 Description: UNKNOWN
 Platform: UNKNOWN
diff --git a/swh.model.egg-info/SOURCES.txt b/swh.model.egg-info/SOURCES.txt
index f88b36d..bd2e46a 100644
--- a/swh.model.egg-info/SOURCES.txt
+++ b/swh.model.egg-info/SOURCES.txt
@@ -1,53 +1,54 @@
 .gitignore
 AUTHORS
 LICENSE
 MANIFEST.in
 Makefile
 Makefile.local
 README-dev.md
 requirements-swh.txt
 requirements.txt
 setup.py
 version.txt
 bin/git-revhash
 bin/swh-revhash
 debian/changelog
 debian/compat
 debian/control
 debian/copyright
 debian/rules
 debian/source/format
 docs/.gitignore
 docs/Makefile
 docs/conf.py
 docs/data-model.rst
 docs/index.rst
 docs/_static/.placeholder
 docs/_templates/.placeholder
+swh/__init__.py
 swh.model.egg-info/PKG-INFO
 swh.model.egg-info/SOURCES.txt
 swh.model.egg-info/dependency_links.txt
 swh.model.egg-info/requires.txt
 swh.model.egg-info/top_level.txt
 swh/model/__init__.py
 swh/model/exceptions.py
 swh/model/from_disk.py
 swh/model/hashutil.py
 swh/model/identifiers.py
 swh/model/merkle.py
 swh/model/validators.py
 swh/model/fields/__init__.py
 swh/model/fields/compound.py
 swh/model/fields/hashes.py
 swh/model/fields/simple.py
 swh/model/tests/__init__.py
 swh/model/tests/generate_testdata_from_disk.py
 swh/model/tests/test_from_disk.py
 swh/model/tests/test_hashutil.py
 swh/model/tests/test_identifiers.py
 swh/model/tests/test_merkle.py
 swh/model/tests/test_validators.py
 swh/model/tests/fields/__init__.py
 swh/model/tests/fields/test_compound.py
 swh/model/tests/fields/test_hashes.py
 swh/model/tests/fields/test_simple.py
\ No newline at end of file
diff --git a/swh/__init__.py b/swh/__init__.py
new file mode 100644
index 0000000..69e3be5
--- /dev/null
+++ b/swh/__init__.py
@@ -0,0 +1 @@
+__path__ = __import__('pkgutil').extend_path(__path__, __name__)
diff --git a/version.txt b/version.txt
index 99574ed..b5266ca 100644
--- a/version.txt
+++ b/version.txt
@@ -1 +1 @@
-v0.0.18-0-g34228c5
\ No newline at end of file
+v0.0.19-0-g0b7f217
\ No newline at end of file