diff --git a/swh/loader/package/__init__.py b/swh/loader/package/__init__.py
--- a/swh/loader/package/__init__.py
+++ b/swh/loader/package/__init__.py
@@ -6,9 +6,12 @@
 
 from typing import Any, Dict, Mapping
 
+import pkg_resources
+
+
 try:
-    from swh.loader.core._version import __version__   # type: ignore
-except ImportError:
+    __version__ = pkg_resources.get_distribution('swh.loader.core').version
+except pkg_resources.DistributionNotFound:
     __version__ = 'devel'
 
 
diff --git a/swh/loader/package/tests/test_utils.py b/swh/loader/package/tests/test_utils.py
--- a/swh/loader/package/tests/test_utils.py
+++ b/swh/loader/package/tests/test_utils.py
@@ -7,9 +7,16 @@
 import os
 import pytest
 
+
+import swh.loader.package
 from swh.loader.package.utils import download, api_info, release_name
 
 
+def test_version_generation():
+    assert swh.loader.package.__version__ != 'devel', \
+        "Make sure swh.loader.core is installed (e.g. pip install -e .)"
+
+
 @pytest.mark.fs
 def test_download_fail_to_download(tmp_path, requests_mock):
     url = 'https://pypi.org/pypi/arrow/json'
@@ -64,6 +71,26 @@
             '1d9224378d77925d612c9f926eb9fb92850e6551def8328011b6a972323298d5')
 
 
+@pytest.mark.fs
+def test_download_headers(tmp_path, requests_mock):
+    """Check that we send proper headers when downloading files"""
+    filename = 'requests-0.0.1.tar.gz'
+    url = 'https://pypi.org/pypi/requests/%s' % filename
+    data = 'this is something'
+    requests_mock.get(url, text=data, headers={
+        'content-length': str(len(data))
+    })
+
+    actual_filepath, actual_hashes = download(url, dest=str(tmp_path))
+
+    assert len(requests_mock.request_history) == 1
+    req = requests_mock.request_history[0]
+    assert 'User-Agent' in req.headers
+    user_agent = req.headers['User-Agent']
+    assert 'Software Heritage Loader' in user_agent
+    assert swh.loader.package.__version__ in user_agent
+
+
 @pytest.mark.fs
 def test_download_ok_with_hashes(tmp_path, requests_mock):
     """Download without issue should provide filename and hashes"""