diff --git a/app/celery/broadcast_message_tasks.py b/app/celery/broadcast_message_tasks.py
index 18ca0225a..31de633cf 100644
--- a/app/celery/broadcast_message_tasks.py
+++ b/app/celery/broadcast_message_tasks.py
@@ -28,8 +28,8 @@ def get_retry_delay(retry_count):
 
     # 2 to the power of x. 1, 2, 4, 8, 16, 32, ...
     delay = 2**retry_count
-    # never wait longer than 5 minutes
-    return min(delay, 300)
+    # never wait longer than 4 minutes
+    return min(delay, 240)
 
 
 def check_provider_message_should_send(broadcast_event, provider):
diff --git a/manifest.yml.j2 b/manifest.yml.j2
index 6f7d16062..8a7cf8832 100644
--- a/manifest.yml.j2
+++ b/manifest.yml.j2
@@ -64,7 +64,9 @@
   'notify-delivery-worker-letters': {'memory': '2G'},
   'notify-delivery-worker-retry-tasks': {},
   'notify-delivery-worker-internal': {},
-  'notify-delivery-worker-broadcasts': {},
+  'notify-delivery-worker-broadcasts': {
+      'CELERYD_PREFETCH_MULTIPLIER': 1,
+  },
   'notify-delivery-worker-receipts': {},
   'notify-delivery-worker-service-callbacks': {'disk_quota': '2G'},
   'notify-delivery-worker-save-api-notifications': {'disk_quota': '2G'},
diff --git a/tests/app/celery/test_broadcast_message_tasks.py b/tests/app/celery/test_broadcast_message_tasks.py
index 28c22d88f..93de72c0e 100644
--- a/tests/app/celery/test_broadcast_message_tasks.py
+++ b/tests/app/celery/test_broadcast_message_tasks.py
@@ -505,7 +505,7 @@ def test_send_broadcast_provider_message_errors(mocker, sample_service, provider
 @pytest.mark.parametrize('num_retries, expected_countdown', [
     (0, 1),
     (5, 32),
-    (20, 300),
+    (20, 240),
 ])
 def test_send_broadcast_provider_message_delays_retry_exponentially(
     mocker,
@@ -587,10 +587,10 @@ def test_trigger_link_tests_invokes_cbc_proxy_client(
     (0, 1),
     (1, 2),
     (2, 4),
-    (8, 256),
-    (9, 300),
-    (10, 300),
-    (1000, 300),
+    (7, 128),
+    (8, 240),
+    (9, 240),
+    (1000, 240),
 ])
 def test_get_retry_delay_has_capped_backoff(retry_count, expected_delay):
     assert get_retry_delay(retry_count) == expected_delay