diff --git a/requirements-azure.txt b/requirements-azure.txt
new file mode 100644
index 0000000..c0e4b0c
--- /dev/null
+++ b/requirements-azure.txt
@@ -0,0 +1 @@
+azure-storage-blob >= 12.0, != 12.9.0  # version 12.9.0 breaks mypy https://github.com/Azure/azure-sdk-for-python/pull/20891
diff --git a/requirements-libcloud.txt b/requirements-libcloud.txt
new file mode 100644
index 0000000..5d1cd7e
--- /dev/null
+++ b/requirements-libcloud.txt
@@ -0,0 +1 @@
+apache-libcloud
diff --git a/requirements-test.txt b/requirements-test.txt
index d197d8d..6366880 100644
--- a/requirements-test.txt
+++ b/requirements-test.txt
@@ -1,11 +1,9 @@
-apache-libcloud
-azure-storage-blob >= 12.0, != 12.9.0  # version 12.9.0 breaks mypy https://github.com/Azure/azure-sdk-for-python/pull/20891
 pytest < 7.0.0  # v7.0.0 removed _pytest.tmpdir.TempdirFactory, which is used by some of the pytest plugins we use
 pytest-asyncio
 pytest-mock
 requests_mock[fixture] >= 1.9
 requests_toolbelt
 types-pyyaml
 types-requests
 pytest-postgresql < 4.0.0  # version 4.0 depends on psycopg 3. https://github.com/ClearcodeHQ/pytest-postgresql/blob/main/CHANGES.rst#400
 
diff --git a/requirements-winery.txt b/requirements-winery.txt
new file mode 100644
index 0000000..a93e1f1
--- /dev/null
+++ b/requirements-winery.txt
@@ -0,0 +1,2 @@
+psycopg2
+sh
diff --git a/requirements.txt b/requirements.txt
index 252f61a..6170110 100644
--- a/requirements.txt
+++ b/requirements.txt
@@ -1,14 +1,9 @@
 # Add here external Python modules dependencies, one per line. Module names
 # should match https://pypi.python.org/pypi names. For the full spec or
 # dependency lines, see https://pip.readthedocs.org/en/1.1/requirements.html
 
-# remote storage API server
 click
-requests
-psycopg2
-sh
 typing-extensions
 
-# optional dependencies
-# apache-libcloud
-# azure-storage-blob >= 12.0
+# seaweedfs backend
+requests
diff --git a/setup.py b/setup.py
index 91c4fd0..1e76487 100755
--- a/setup.py
+++ b/setup.py
@@ -1,70 +1,78 @@
 #!/usr/bin/env python3
 # Copyright (C) 2015-2020  The Software Heritage developers
 # See the AUTHORS file at the top-level directory of this distribution
 # License: GNU General Public License version 3, or any later version
 # See top-level LICENSE file for more information
 
 from io import open
 from os import path
 
 from setuptools import find_packages, setup
 
 here = path.abspath(path.dirname(__file__))
 
 # Get the long description from the README file
 with open(path.join(here, "README.md"), encoding="utf-8") as f:
     long_description = f.read()
 
 
 def parse_requirements(name=None):
     if name:
         reqf = "requirements-%s.txt" % name
     else:
         reqf = "requirements.txt"
 
     requirements = []
     if not path.exists(reqf):
         return requirements
 
     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
 
 
 setup(
     name="swh.objstorage",
     description="Software Heritage Object Storage",
     long_description=long_description,
     long_description_content_type="text/markdown",
     python_requires=">=3.7",
     author="Software Heritage developers",
     author_email="swh-devel@inria.fr",
     url="https://forge.softwareheritage.org/diffusion/DOBJS",
     packages=find_packages(),
     install_requires=parse_requirements() + parse_requirements("swh"),
     setup_requires=["setuptools-scm"],
     use_scm_version=True,
-    extras_require={"testing": parse_requirements("test")},
+    extras_require={
+        "testing": parse_requirements("test")
+        + parse_requirements("azure")
+        + parse_requirements("libcloud")
+        + parse_requirements("winery"),
+        "azure": parse_requirements("azure"),
+        "libcloud": parse_requirements("libcloud"),
+        "winery": parse_requirements("winery"),
+    },
     include_package_data=True,
     entry_points="""
         [swh.cli.subcommands]
         objstorage=swh.objstorage.cli
     """,
     classifiers=[
         "Programming Language :: Python :: 3",
         "Intended Audience :: Developers",
         "License :: OSI Approved :: GNU General Public License v3 (GPLv3)",
         "Operating System :: OS Independent",
         "Development Status :: 5 - Production/Stable",
     ],
     project_urls={
         "Bug Reports": "https://forge.softwareheritage.org/maniphest",
         "Funding": "https://www.softwareheritage.org/donate",
         "Source": "https://forge.softwareheritage.org/source/swh-objstorage",
         "Documentation": "https://docs.softwareheritage.org/devel/swh-objstorage/",
     },
 )