diff --git a/microversion_parse/__init__.py b/microversion_parse/__init__.py
index cc956ac..f5ab455 100644
--- a/microversion_parse/__init__.py
+++ b/microversion_parse/__init__.py
@@ -19,7 +19,7 @@ import collections
 STANDARD_HEADER = 'openstack-api-version'
 
 
-def get_version(headers, service_type=None, legacy_headers=None):
+def get_version(headers, service_type, legacy_headers=None):
     """Parse a microversion out of headers
 
     :param headers: The headers of a request, dict or list
@@ -46,8 +46,6 @@ def get_version(headers, service_type=None, legacy_headers=None):
     Folded headers are joined by ','.
     """
 
-    assert service_type, 'service type required'
-
     folded_headers = fold_headers(headers)
 
     version = check_standard_header(folded_headers, service_type)
diff --git a/microversion_parse/tests/test_get_version.py b/microversion_parse/tests/test_get_version.py
index 5121c9e..bc87362 100644
--- a/microversion_parse/tests/test_get_version.py
+++ b/microversion_parse/tests/test_get_version.py
@@ -194,10 +194,6 @@ class TestGetHeaders(testtools.TestCase):
             headers, service_type='compute')
         self.assertEqual(None, version)
 
-        self.assertRaises(AssertionError,
-                          microversion_parse.get_version,
-                          headers)
-
     def test_unfolded_service(self):
         headers = [
             ('header-one', 'alpha'),