diff --git a/flake8/options/manager.py b/flake8/options/manager.py
index baccd95..a471960 100644
--- a/flake8/options/manager.py
+++ b/flake8/options/manager.py
@@ -105,8 +105,10 @@ class Option(object):
 
     def to_optparse(self):
         """Convert a Flake8 Option to an optparse Option."""
-        return optparse.Option(*self.option_args,
-                               **self.option_kwargs)
+        if not hasattr(self, '_opt'):
+            self._opt = optparse.Option(*self.option_args,
+                                        **self.option_kwargs)
+        return self._opt
 
 
 class OptionManager(object):
@@ -130,6 +132,8 @@ class OptionManager(object):
             ``short_option_name`` and ``long_option_name`` may be specified
             positionally as they are with optparse normally.
         """
+        if len(args) == 1 and args[0].startswith('--'):
+            args = (None, args[0])
         option = Option(*args, **kwargs)
         self.parser.add_option(option.to_optparse())
         self.options.append(option)
diff --git a/tests/unit/test_option_manager.py b/tests/unit/test_option_manager.py
new file mode 100644
index 0000000..27c47d6
--- /dev/null
+++ b/tests/unit/test_option_manager.py
@@ -0,0 +1,46 @@
+"""Unit tests for flake.options.manager.OptionManager."""
+import optparse
+
+import pytest
+
+from flake8.options import manager
+
+
+@pytest.fixture
+def optmanager():
+    return manager.OptionManager(prog='flake8', version='3.0.0b1')
+
+
+def test_option_manager_creates_option_parser(optmanager):
+    """Verify that a new manager creates a new parser."""
+    assert optmanager.parser is not None
+    assert isinstance(optmanager.parser, optparse.OptionParser) is True
+
+
+def test_add_option_short_option_only(optmanager):
+    """Verify the behaviour of adding a short-option only."""
+    assert optmanager.options == []
+    assert optmanager.config_options_dict == {}
+
+    optmanager.add_option('-s', help='Test short opt')
+    assert optmanager.options[0].short_option_name == '-s'
+
+
+def test_add_option_long_option_only(optmanager):
+    """Verify the behaviour of adding a long-option only."""
+    assert optmanager.options == []
+    assert optmanager.config_options_dict == {}
+
+    optmanager.add_option('--long', help='Test long opt')
+    assert optmanager.options[0].short_option_name is None
+    assert optmanager.options[0].long_option_name == '--long'
+
+
+def test_add_short_and_long_option_names(optmanager):
+    """Verify the behaviour of using both short and long option names."""
+    assert optmanager.options == []
+    assert optmanager.config_options_dict == {}
+
+    optmanager.add_option('-b', '--both', help='Test both opts')
+    assert optmanager.options[0].short_option_name == '-b'
+    assert optmanager.options[0].long_option_name == '--both'