diff --git a/tests/test_schemas.py b/tests/test_schemas.py
index 262989d5..2028f8d1 100644
--- a/tests/test_schemas.py
+++ b/tests/test_schemas.py
@@ -162,25 +162,28 @@ def test_property_count(self):
         assert stats
 
     def test_types(self):
-        '''
+        """
         Every property in a schema should have a type defined
-        '''
+        """
         errs = []
         for schema_name in SCHEMA_FILES:
             with open(os.path.join(SCHEMAS_DIR, schema_name)) as json_schema:
                 schema = json.load(json_schema)
 
             if schema_name != "common.json":
-                for prop, fields in schema['properties'].items():
+                for prop, fields in schema["properties"].items():
                     if "type" not in fields and "$ref" not in fields:
                         errs.append((schema_name, prop))
             else:
                 if "type" not in fields:
                     errs.append((schema_name, prop))
-        assert not errs, (
-                "The following schemata do not have types defined:\n\t"
-                + "\n\t".join("- {} schema has property '{}' missing a 'type'".format(e[0], e[1]) for e in errs)
-                )
+        assert (
+            not errs
+        ), "The following schemata do not have types defined:\n\t" + "\n\t".join(
+            "- {} schema has property '{}' missing a 'type'".format(e[0], e[1])
+            for e in errs
+        )
+
 
 class TestExamples:
     with open(os.path.join(SCHEMAS_DIR, "example.json")) as ff: