diff --git a/microversion_parse/__init__.py b/microversion_parse/__init__.py
index f5ab455..cb3fe63 100644
--- a/microversion_parse/__init__.py
+++ b/microversion_parse/__init__.py
@@ -90,8 +90,7 @@ def fold_headers(headers):
     # If it behaves like a dict, return it. Webob uses objects which
     # are not dicts, but behave like them.
     if hasattr(headers, 'keys'):
-        # TODO(cdent): canonicalize? (i.e. in lower())
-        return headers
+        return dict((k.lower(), v) for k, v in headers.items())
     header_dict = collections.defaultdict(list)
     for header, value in headers:
         header_dict[header.lower()].append(value.strip())
diff --git a/microversion_parse/tests/test_get_version.py b/microversion_parse/tests/test_get_version.py
index bc87362..fa16681 100644
--- a/microversion_parse/tests/test_get_version.py
+++ b/microversion_parse/tests/test_get_version.py
@@ -216,3 +216,12 @@ class TestGetHeaders(testtools.TestCase):
             headers, service_type='compute',
             legacy_headers=['x-openstack-nova-api-version'])
         self.assertEqual('2.0', version)
+
+    def test_capitalized_headers(self):
+        headers = {
+            'X-Openstack-Ironic-Api-Version': '123.456'
+        }
+        version = microversion_parse.get_version(
+            headers, service_type='ironic',
+            legacy_headers=['X-Openstack-Ironic-Api-Version'])
+        self.assertEqual('123.456', version)
diff --git a/microversion_parse/tests/test_webob.py b/microversion_parse/tests/test_webob.py
index ce0b58e..a2e36c8 100644
--- a/microversion_parse/tests/test_webob.py
+++ b/microversion_parse/tests/test_webob.py
@@ -30,7 +30,8 @@ class TestWebobHeaders(testtools.TestCase):
 
         folded_headers = microversion_parse.fold_headers(headers)
         self.assertEqual(3, len(folded_headers))
-        self.assertEqual(set(headers.keys()), set(folded_headers.keys()))
+        self.assertEqual(set(['header-one', 'header-three', 'header-two']),
+                         set(folded_headers.keys()))
         self.assertEqual('gamma', folded_headers['header-three'])
 
     def test_simple_match(self):