diff --git a/lms/tasks/roster.py b/lms/tasks/roster.py
index 172bf9e22e..e012b20191 100644
--- a/lms/tasks/roster.py
+++ b/lms/tasks/roster.py
@@ -114,9 +114,8 @@ def schedule_fetching_assignment_rosters() -> None:
 
     # Only fetch rosters for assignments that have been recently launched
     recent_launches_clause = exists(
-        select(Event)
-        .join(Assignment, Event.assignment_id == Assignment.id)
-        .where(
+        select(Event).where(
+            Event.assignment_id == Assignment.id,
             Event.timestamp >= now - LAUNCHED_WINDOW,
         )
     )
diff --git a/tests/unit/lms/tasks/roster_test.py b/tests/unit/lms/tasks/roster_test.py
index 2beec85f41..7774f39f83 100644
--- a/tests/unit/lms/tasks/roster_test.py
+++ b/tests/unit/lms/tasks/roster_test.py
@@ -42,6 +42,7 @@ def test_schedule_fetching_rosters(
     @freeze_time("2024-08-28")
     @pytest.mark.usefixtures(
         "lms_course_with_no_launch",
+        "lms_course_with_no_recent_launch",
         "lms_course_with_no_service_url",
         "lms_course_with_launch_and_recent_roster",
         "lms_course_with_recent_launch_and_task_done_row",
@@ -60,6 +61,7 @@ def test_schedule_fetching_course_rosters(
     @freeze_time("2024-08-28")
     @pytest.mark.usefixtures(
         "assignment_with_no_launch",
+        "assignment_with_no_recent_launch",
         "assignment_with_no_lti_v13_id",
         "assignment_with_recent_launch_and_task_done_row",
         "assignment_with_launch_and_recent_roster",
@@ -93,6 +95,17 @@ def assignment_with_no_launch(self):
             lti_v13_resource_link_id="ID", course=factories.Course()
         )
 
+    @pytest.fixture
+    def assignment_with_no_recent_launch(self, lms_course_with_recent_launch):
+        assignment = factories.Assignment(
+            lti_v13_resource_link_id="ID", course=lms_course_with_recent_launch.course
+        )
+        factories.Event(
+            assignment=assignment,
+            timestamp=datetime(2024, 1, 1),
+        )
+        return assignment
+
     @pytest.fixture
     def lms_course_with_recent_launch(self):
         course = factories.Course()
@@ -107,6 +120,20 @@ def lms_course_with_recent_launch(self):
             course=course,
         )
 
+    @pytest.fixture
+    def lms_course_with_no_recent_launch(self):
+        course = factories.Course()
+        factories.Event(
+            course=course,
+            timestamp=datetime(2024, 1, 1),
+        )
+
+        return factories.LMSCourse(
+            lti_context_memberships_url="URL",
+            h_authority_provided_id=course.authority_provided_id,
+            course=course,
+        )
+
     @pytest.fixture
     def lms_course_with_recent_launch_and_task_done_row(self, db_session):
         course = factories.Course()