diff --git a/src/flake8/options/manager.py b/src/flake8/options/manager.py
index 3aea4ad..f745388 100644
--- a/src/flake8/options/manager.py
+++ b/src/flake8/options/manager.py
@@ -437,7 +437,9 @@ class OptionManager(object):
         assert isinstance(  # nosec (for bandit)
             self.parser, argparse.ArgumentParser
         ), self.parser
-        parsed_args = self.parser.parse_args(args, values)
+        if values:
+            self.parser.set_defaults(**vars(values))
+        parsed_args = self.parser.parse_args(args)
         # TODO: refactor callers to not need this
         return parsed_args, parsed_args.filenames
 
diff --git a/tests/unit/test_option_manager.py b/tests/unit/test_option_manager.py
index b6ea55c..859dca1 100644
--- a/tests/unit/test_option_manager.py
+++ b/tests/unit/test_option_manager.py
@@ -29,6 +29,14 @@ def test_parse_args_forwarding_default_values(optmanager):
     assert options.foo == 'bar'
 
 
+def test_parse_args_forwarding_type_coercion(optmanager):
+    """Verify default provided values are type converted from add_option."""
+    optmanager.add_option('--foo', type=int)
+    namespace = argparse.Namespace(foo='5')
+    options, args = optmanager.parse_args([], namespace)
+    assert options.foo == 5
+
+
 def test_add_option_short_option_only(optmanager):
     """Verify the behaviour of adding a short-option only."""
     assert optmanager.options == []