diff -uNrp a/requests/certs.py b/requests/certs.py
--- a/requests/certs.py	2019-12-20 15:17:38.304000000 +0800
+++ b/requests/certs.py	2019-12-20 15:25:18.952000000 +0800
@@ -11,7 +11,10 @@ If you are packaging Requests, e.g., for
 environment, you can change the definition of where() to return a separately
 packaged CA bundle.
 """
-from certifi import where
+def where():
+    """Return the absolute path to the system CA bundle."""
+    return '/etc/pki/tls/certs/ca-bundle.crt'
+
 
 if __name__ == '__main__':
     print(where())
diff -uNrp a/setup.py b/setup.py
--- a/setup.py	2019-12-20 15:17:38.304000000 +0800
+++ b/setup.py	2019-12-20 15:14:39.212000000 +0800
@@ -45,7 +45,6 @@ requires = [
     'chardet>=3.0.2,<3.1.0',
     'idna>=2.5,<2.9',
     'urllib3>=1.21.1,<1.25',
-    'certifi>=2017.4.17'
 
 ]
 test_requirements = [