foo.diff

diff --git a/django/db/migrations/writer.py b/django/db/migrations/writer.py
index 9709eec..e5e9f7a 100644
--- a/django/db/migrations/writer.py
+++ b/django/db/migrations/writer.py
@@ -352,7 +352,7 @@ class MigrationWriter(object):
                     return string, set(imports)
             if hasattr(value, "__module__"):
                 module = value.__module__
-                if module == 'builtins' if six.PY3 else '__builtin__':
+                if module == ('builtins' if six.PY3 else '__builtin__'):
                     return value.__name__, set()
                 else:
                     return "%s.%s" % (module, value.__name__), set(["import %s" % module])