diff --git a/common/djangoapps/student/tests/factories.py b/common/djangoapps/student/tests/factories.py
index 90d4f30a79..d948e9ec92 100644
--- a/common/djangoapps/student/tests/factories.py
+++ b/common/djangoapps/student/tests/factories.py
@@ -135,7 +135,7 @@ class CourseEnrollmentFactory(DjangoModelFactory):
     def _create(cls, model_class, *args, **kwargs):
         manager = cls._get_manager(model_class)
         course_kwargs = {}
-        for key in kwargs.keys():
+        for key in list(kwargs):
             if key.startswith('course__'):
                 course_kwargs[key.split('__')[1]] = kwargs.pop(key)