diff --git a/zerver/actions/message_edit.py b/zerver/actions/message_edit.py
index 1772f4aceb..d16a711813 100644
--- a/zerver/actions/message_edit.py
+++ b/zerver/actions/message_edit.py
@@ -506,6 +506,7 @@ def do_update_message(
         edit_history_event["prev_stream"] = stream_being_edited.id
         edit_history_event["stream"] = new_stream.id
         event[ORIG_TOPIC] = orig_topic_name
+        assert new_stream.recipient_id is not None
         target_message.recipient_id = new_stream.recipient_id
 
         event["new_stream_id"] = new_stream.id
@@ -762,6 +763,7 @@ def do_update_message(
             # query. But it's nice to reuse code, and this bulk
             # operation is likely cheaper than a `GET /messages`
             # unless the topic has thousands of messages of history.
+            assert stream_being_edited.recipient_id is not None
             unmoved_messages = messages_for_topic(
                 stream_being_edited.recipient_id,
                 orig_topic_name,
diff --git a/zerver/actions/streams.py b/zerver/actions/streams.py
index 51ea3d53cf..6b3602b703 100644
--- a/zerver/actions/streams.py
+++ b/zerver/actions/streams.py
@@ -789,6 +789,7 @@ def do_change_stream_permission(
         if old_invite_only_value != stream.invite_only:
             # Reset the Attachment.is_realm_public cache for all
             # messages in the stream whose permissions were changed.
+            assert stream.recipient_id is not None
             Attachment.objects.filter(messages__recipient_id=stream.recipient_id).update(
                 is_realm_public=None
             )
@@ -832,6 +833,7 @@ def do_change_stream_permission(
         if old_is_web_public_value != stream.is_web_public:
             # Reset the Attachment.is_realm_public cache for all
             # messages in the stream whose permissions were changed.
+            assert stream.recipient_id is not None
             Attachment.objects.filter(messages__recipient_id=stream.recipient_id).update(
                 is_web_public=None
             )
diff --git a/zerver/actions/user_topics.py b/zerver/actions/user_topics.py
index 5e18c90139..ec00e5db7a 100644
--- a/zerver/actions/user_topics.py
+++ b/zerver/actions/user_topics.py
@@ -19,6 +19,7 @@ def do_mute_topic(
 ) -> None:
     if date_muted is None:
         date_muted = timezone_now()
+    assert stream.recipient_id is not None
     add_topic_mute(
         user_profile,
         stream.id,
diff --git a/zerver/lib/streams.py b/zerver/lib/streams.py
index f0e5d835cc..f98044857b 100644
--- a/zerver/lib/streams.py
+++ b/zerver/lib/streams.py
@@ -358,6 +358,7 @@ def access_stream_common(
         raise AssertionError("user_profile and stream realms don't match")
 
     try:
+        assert stream.recipient_id is not None
         sub = Subscription.objects.get(
             user_profile=user_profile, recipient_id=stream.recipient_id, active=require_active
         )
diff --git a/zerver/lib/test_helpers.py b/zerver/lib/test_helpers.py
index 61bf77d00a..051b3ed6ed 100644
--- a/zerver/lib/test_helpers.py
+++ b/zerver/lib/test_helpers.py
@@ -271,6 +271,7 @@ def most_recent_message(user_profile: UserProfile) -> Message:
 def get_subscription(stream_name: str, user_profile: UserProfile) -> Subscription:
     stream = get_stream(stream_name, user_profile.realm)
     recipient_id = stream.recipient_id
+    assert recipient_id is not None
     return Subscription.objects.get(
         user_profile=user_profile, recipient_id=recipient_id, active=True
     )
diff --git a/zerver/lib/user_topics.py b/zerver/lib/user_topics.py
index 0ead16824e..18595a8ad8 100644
--- a/zerver/lib/user_topics.py
+++ b/zerver/lib/user_topics.py
@@ -49,6 +49,7 @@ def set_topic_mutes(
     for stream_name, topic_name in muted_topics:
         stream = get_stream(stream_name, user_profile.realm)
         recipient_id = stream.recipient_id
+        assert recipient_id is not None
 
         add_topic_mute(
             user_profile=user_profile,
diff --git a/zerver/views/streams.py b/zerver/views/streams.py
index ec573b2889..d301bddf60 100644
--- a/zerver/views/streams.py
+++ b/zerver/views/streams.py
@@ -792,6 +792,7 @@ def get_topics_backend(
 
         (stream, sub) = access_stream_by_id(user_profile, stream_id)
 
+        assert stream.recipient_id is not None
         result = get_topic_history_for_stream(
             user_profile=user_profile,
             recipient_id=stream.recipient_id,