diff --git a/lms/djangoapps/grades/tasks.py b/lms/djangoapps/grades/tasks.py
index ce0c7e6504..4802ee9da2 100644
--- a/lms/djangoapps/grades/tasks.py
+++ b/lms/djangoapps/grades/tasks.py
@@ -32,8 +32,10 @@ def recalculate_subsection_grade(user_id, course_id, usage_id, only_if_higher):
         be updated only if the new grade is higher than the previous
         value.
     """
-    course_key = CourseLocator.from_string(course_id)
+    if not PersistentGradesEnabledFlag.feature_enabled(course_id):
+        return
 
+    course_key = CourseLocator.from_string(course_id)
     student = User.objects.get(id=user_id)
     scored_block_usage_key = UsageKey.from_string(usage_id).replace(course_key=course_key)
 
diff --git a/lms/djangoapps/grades/tests/test_tasks.py b/lms/djangoapps/grades/tests/test_tasks.py
index 5379338846..5e7877611d 100644
--- a/lms/djangoapps/grades/tests/test_tasks.py
+++ b/lms/djangoapps/grades/tests/test_tasks.py
@@ -178,7 +178,7 @@ class RecalculateSubsectionGradeTest(ModuleStoreTestCase):
         with self.store.default_store(default_store):
             self.set_up_course(enable_subsection_grades=False)
             self.assertFalse(PersistentGradesEnabledFlag.feature_enabled(self.course.id))
-            with check_mongo_calls(2) and self.assertNumQueries(2):
+            with check_mongo_calls(2) and self.assertNumQueries(0):
                 recalculate_subsection_grade.apply(args=tuple(self.score_changed_kwargs.values()))
 
     @skip("Pending completion of TNL-5089")