commit - f0daf70250f11e3a337bbb4f768b9fc6683d3a23
commit + 6b1189b300b2ffc6054060b4265205b4245273fd
blob - 919ee6f018eaf78792300bfa5e6567b7ea3cf358
blob + 7342c577fe317795f76fe5f0045d4288dbbb048e
--- .github/workflows/pythonpackage.yml
+++ .github/workflows/pythonpackage.yml
@@ -44,7 +44,7 @@ jobs:
         if: "matrix.os != 'windows-latest' && matrix.python-version != 'pypy3'"
       - name: Install mypy
         run: |
-          pip install -U mypy types-paramiko types-certifi types-requests
+          pip install -U mypy types-paramiko types-requests
         if: "matrix.python-version != 'pypy3'"
       - name: Style checks
         run: |
blob - c413ebbbe6dd4bd9cfcfa7b25c8e972f8245facf
blob + 191aa74318864fdf1ccf8477f833335955a324e0
--- dulwich/client.py
+++ dulwich/client.py
@@ -1863,7 +1863,9 @@ def default_urllib3_manager(   # noqa: C901
 
     headers = {"User-agent": user_agent}
 
-    kwargs = {}
+    kwargs = {
+        "ca_certs" : ca_certs,
+    }
     if ssl_verify is True:
         kwargs["cert_reqs"] = "CERT_REQUIRED"
     elif ssl_verify is False:
@@ -1872,19 +1874,8 @@ def default_urllib3_manager(   # noqa: C901
         # Default to SSL verification
         kwargs["cert_reqs"] = "CERT_REQUIRED"
 
-    if ca_certs is not None:
-        kwargs["ca_certs"] = ca_certs
     kwargs.update(override_kwargs)
 
-    # Try really hard to find a SSL certificate path
-    if "ca_certs" not in kwargs and kwargs.get("cert_reqs") != "CERT_NONE":
-        try:
-            import certifi
-        except ImportError:
-            pass
-        else:
-            kwargs["ca_certs"] = certifi.where()
-
     import urllib3
 
     if proxy_server is not None:
blob - 60ab5e4608f44b9da7fc96c9f5e174a209124b71
blob + 197b023134f1b9bbfd9ea0422d40ae82f2133d8f
--- setup.py
+++ setup.py
@@ -91,7 +91,7 @@ setup(name='dulwich',
       ext_modules=ext_modules,
       zip_safe=False,
       distclass=DulwichDistribution,  # type: ignore
-      install_requires=['urllib3>=1.24.1', 'certifi'],
+      install_requires=['urllib3>=1.25'],
       include_package_data=True,
       test_suite='dulwich.tests.test_suite',
       tests_require=tests_require,