diff --git a/certbot-apache/certbot_apache/tests/ocsp_prefetch_test.py b/certbot-apache/certbot_apache/tests/ocsp_prefetch_test.py
index 9fa0c57a4..5985fc37d 100644
--- a/certbot-apache/certbot_apache/tests/ocsp_prefetch_test.py
+++ b/certbot-apache/certbot_apache/tests/ocsp_prefetch_test.py
@@ -13,6 +13,7 @@ from acme.magic_typing import Dict, List, Set, Union  # pylint: disable=unused-i
 from certbot import errors
 from certbot_apache.tests import util
 
+
 class MockDBM(object):
     # pylint: disable=missing-docstring
     """Main mock DBM class for Py3 dbm module"""
@@ -125,10 +126,19 @@ class OCSPPrefetchTest(util.ApacheTest):
 
     def call_mocked_py3(self, func, *args, **kwargs):
         """Calls methods with imports mocked to suit Py3 environment"""
-        if 'bsddb' in sys.modules.keys():
-            sys.modules['bsddb'] = None
-        sys.modules['dbm'] = MockDBM()
-        return self._call_mocked(func, *args, **kwargs)
+        real_import = six.moves.builtins.__import__
+
+        def mock_import(*args, **kwargs):
+            """Mock import to raise ImportError for Py2 specific module to make
+            ApacheConfigurator pick the correct one for Python3 regardless of the
+            python version the tests are running under."""
+            if args[0] == "bsddb":
+                raise ImportError
+            return real_import(*args, **kwargs)
+
+        with mock.patch('six.moves.builtins.__import__', side_effect=mock_import):
+            sys.modules['dbm'] = MockDBM()
+            return self._call_mocked(func, *args, **kwargs)
 
     @mock.patch("certbot_apache.override_debian.DebianConfigurator.enable_mod")
     def test_ocsp_prefetch_enable_mods(self, mock_enable):
@@ -259,9 +269,11 @@ class OCSPPrefetchTest(util.ApacheTest):
     def test_ocsp_prefetch_preflight_check_noerror(self):
         self.call_mocked_py2(self.config._ensure_ocsp_prefetch_compatibility)
         self.call_mocked_py3(self.config._ensure_ocsp_prefetch_compatibility)
-        with mock.patch("dbm.ndbm") as mock_ndbm:
-            mock_ndbm.library = 'Not Berkeley DB'
+        mockdbm_path = "certbot_apache.tests.ocsp_prefetch_test.Mockdbm_impl"
+        with mock.patch(mockdbm_path) as mock_dbm:
+            mock_dbm.library = 'Not Berkeley DB'
             self.assertRaises(errors.NotSupportedError,
+                              self.call_mocked_py3,
                               self.config._ensure_ocsp_prefetch_compatibility)
 
     def test_ocsp_prefetch_open_dbm_no_file(self):
@@ -306,7 +318,7 @@ class OCSPPrefetchTest(util.ApacheTest):
         db = self.call_mocked_py3(
             self.config._ocsp_dbm_open, self.db_path)
         db[b'key'] = expected_val
-        self.call_mocked_py2(self.config._ocsp_dbm_close, db)
+        self.call_mocked_py3(self.config._ocsp_dbm_close, db)
         db2 = self.call_mocked_py3(self.config._ocsp_dbm_open, self.db_path)
         self.assertEquals(db2[b'key'], expected_val)