diff --git a/deltachat-rpc-client/src/deltachat_rpc_client/account.py b/deltachat-rpc-client/src/deltachat_rpc_client/account.py
index 6f919f71e..b5a002ae9 100644
--- a/deltachat-rpc-client/src/deltachat_rpc_client/account.py
+++ b/deltachat-rpc-client/src/deltachat_rpc_client/account.py
@@ -439,6 +439,12 @@ class Account:
         """Wait for reaction change event."""
         return self.wait_for_event(EventType.REACTIONS_CHANGED)
 
+    def wait_for_imap_inbox_idle(self):
+        """Wait until all messages are fetched,
+        and the IMAP loop enters IDLE mode.
+        """
+        self.wait_for_event(EventType.IMAP_INBOX_IDLE)
+
     def get_fresh_messages_in_arrival_order(self) -> list[Message]:
         """Return fresh messages list sorted in the order of their arrival, with ascending IDs."""
         warn(
diff --git a/deltachat-rpc-client/tests/test_securejoin.py b/deltachat-rpc-client/tests/test_securejoin.py
index 31f483520..4d557bd69 100644
--- a/deltachat-rpc-client/tests/test_securejoin.py
+++ b/deltachat-rpc-client/tests/test_securejoin.py
@@ -112,6 +112,98 @@ def test_qr_securejoin(acfactory, protect):
     fiona.wait_for_securejoin_joiner_success()
 
 
+@pytest.mark.parametrize("all_devices_online", [True, False])
+def test_qr_securejoin_broadcast(acfactory, all_devices_online):
+    alice, bob, fiona = acfactory.get_online_accounts(3)
+
+    alice2 = alice.clone()
+    bob2 = bob.clone()
+
+    if all_devices_online:
+        alice2.start_io()
+        bob2.start_io()
+
+    logging.info("Alice creates a broadcast")
+    alice_chat = alice.create_broadcast("Broadcast channel for everyone!")
+
+    logging.info("Bob joins the broadcast")
+
+    qr_code = alice_chat.get_qr_code()
+    bob.secure_join(qr_code)
+    alice.wait_for_securejoin_inviter_success()
+    bob.wait_for_securejoin_joiner_success()
+
+    snapshot = bob.wait_for_incoming_msg().get_snapshot()
+    assert snapshot.text == f"Member Me added by {alice.get_config('addr')}."
+
+    alice_chat.send_text("Hello everyone!")
+    snapshot = bob.wait_for_incoming_msg().get_snapshot()
+    assert snapshot.text == "Hello everyone!"
+
+    def check_account(ac, contact, inviter_side, please_wait_info_msg=False):
+        # Check that the chat partner is verified.
+        contact_snapshot = contact.get_snapshot()
+        assert contact_snapshot.is_verified
+
+        chat = ac.get_chatlist()[0]
+        chat_msgs = chat.get_messages()
+
+        if please_wait_info_msg:
+            first_msg = chat_msgs.pop(0).get_snapshot()
+            assert first_msg.text == "Establishing guaranteed end-to-end encryption, please wait…"
+            assert first_msg.is_info
+
+        encrypted_msg = chat_msgs[0].get_snapshot()
+        assert encrypted_msg.text == "Messages are end-to-end encrypted."
+        assert encrypted_msg.is_info
+
+        member_added_msg = chat_msgs[1].get_snapshot()
+        if inviter_side:
+            assert member_added_msg.text == f"Member {contact_snapshot.display_name} added."
+        else:
+            assert member_added_msg.text == f"Member Me added by {contact_snapshot.display_name}."
+        assert member_added_msg.is_info
+
+        hello_msg = chat_msgs[2].get_snapshot()
+        assert hello_msg.text == "Hello everyone!"
+        assert not hello_msg.is_info
+
+        assert len(chat_msgs) == 3
+
+        chat_snapshot = chat.get_basic_snapshot()  # TODO or get_full_snapshot()
+        assert chat_snapshot.is_encrypted
+
+        # TODO check more things
+
+    check_account(alice, alice.create_contact(bob), inviter_side=True)
+    check_account(bob, bob.create_contact(alice), inviter_side=False, please_wait_info_msg=True)
+
+    logging.info("===================== Test Alice's second device =====================")
+
+    # Start second Alice device, if it wasn't started already.
+    alice2.start_io()
+    alice2.wait_for_securejoin_inviter_success()
+    alice2.wait_for_imap_inbox_idle()
+    check_account(alice2, alice2.create_contact(bob), inviter_side=True)
+
+    logging.info("===================== Test Bob's second device =====================")
+
+    # Start second Bob device, if it wasn't started already.
+    bob2.start_io()
+    bob2.wait_for_securejoin_joiner_success()
+    bob2.wait_for_imap_inbox_idle()
+    check_account(bob2, bob2.create_contact(alice), inviter_side=False)
+
+    # The QR code token is synced, so alice2 must be able to handle join requests.
+    logging.info("Fiona joins the group via alice2")
+    alice.stop_io()
+    fiona.secure_join(qr_code)
+    alice2.wait_for_securejoin_inviter_success()
+    fiona.wait_for_securejoin_joiner_success()
+
+    # TODO test that Fiona is in the channel correctly
+
+
 def test_qr_securejoin_contact_request(acfactory) -> None:
     """Alice invites Bob to a group when Bob's chat with Alice is in a contact request mode."""
     alice, bob = acfactory.get_online_accounts(2)
diff --git a/deltachat-rpc-client/tox.ini b/deltachat-rpc-client/tox.ini
index 2ad52b8f5..42da40ba2 100644
--- a/deltachat-rpc-client/tox.ini
+++ b/deltachat-rpc-client/tox.ini
@@ -6,7 +6,7 @@ envlist =
 
 [testenv]
 commands =
-    pytest -n6 {posargs}
+    pytest {posargs}
 setenv =
 # Avoid stack overflow when Rust core is built without optimizations.
     RUST_MIN_STACK=8388608
@@ -25,6 +25,6 @@ commands =
     ruff check src/ examples/ tests/
 
 [pytest]
-timeout = 300
+timeout = 30
 log_cli = true
 log_level = debug
diff --git a/src/chat.rs b/src/chat.rs
index 4e7382be1..6fc97488f 100644
--- a/src/chat.rs
+++ b/src/chat.rs
@@ -601,11 +601,23 @@ impl ChatId {
             || chat.is_device_talk()
             || chat.is_self_talk()
             || (!chat.can_send(context).await? && !chat.is_contact_request())
+            // For chattype InBrodacast, the info message is added when the member-added message is received
+            // by directly calling add_encrypted_msg():
+            || chat.typ == Chattype::InBroadcast
             || chat.blocked == Blocked::Yes
         {
             return Ok(());
         }
 
+        self.add_encrypted_msg(context, timestamp_sort).await?;
+        Ok(())
+    }
+
+    pub(crate) async fn add_encrypted_msg(
+        self,
+        context: &Context,
+        timestamp_sort: i64,
+    ) -> Result<()> {
         let text = stock_str::messages_e2e_encrypted(context).await;
         add_info_msg_with_cmd(
             context,
@@ -3817,10 +3829,17 @@ pub(crate) async fn create_broadcast_ex(
     chat_name: String,
     secret: String,
 ) -> Result<ChatId> {
-    let row_id = {
+    let chat_name = sanitize_single_line(&chat_name);
+    if chat_name.is_empty() {
+        bail!("Invalid broadcast channel name: {chat_name}.");
+    }
+
+    let timestamp = create_smeared_timestamp(context);
+    let chat_id = {
         let chat_name = &chat_name;
         let grpid = &grpid;
-        let trans_fn = |t: &mut rusqlite::Transaction| {
+        let trans_fn = |t: &mut rusqlite::Transaction| -> Result<u32> {
+            // TODO it's not needed to lookup an existing broadcast here
             let cnt = t.execute("UPDATE chats SET name=? WHERE grpid=?", (chat_name, grpid))?;
             ensure!(cnt <= 1, "{cnt} chats exist with grpid {grpid}");
             if cnt == 1 {
@@ -3828,7 +3847,7 @@ pub(crate) async fn create_broadcast_ex(
                     "SELECT id FROM chats WHERE grpid=? AND type=?",
                     (grpid, Chattype::OutBroadcast),
                     |row| {
-                        let id: isize = row.get(0)?;
+                        let id: u32 = row.get(0)?;
                         Ok(id)
                     },
                 )?);
@@ -3837,23 +3856,20 @@ pub(crate) async fn create_broadcast_ex(
                 "INSERT INTO chats \
                 (type, name, grpid, created_timestamp) \
                 VALUES(?, ?, ?, ?);",
-                (
-                    Chattype::OutBroadcast,
-                    &chat_name,
-                    &grpid,
-                    create_smeared_timestamp(context),
-                ),
+                (Chattype::OutBroadcast, &chat_name, &grpid, timestamp),
             )?;
             let chat_id = t.last_insert_rowid();
             t.execute(SQL_INSERT_BROADCAST_SECRET, (chat_id, &secret))?;
-            Ok(t.last_insert_rowid().try_into()?)
+            Ok(chat_id.try_into()?)
         };
         context.sql.transaction(trans_fn).await?
     };
-    let chat_id = ChatId::new(u32::try_from(row_id)?);
+    let chat_id = ChatId::new(chat_id);
+    chat_id.maybe_add_encrypted_msg(context, timestamp).await?;
 
     context.emit_msgs_changed_without_ids();
     chatlist_events::emit_chatlist_changed(context);
+    chatlist_events::emit_chatlist_item_changed(context, chat_id);
 
     if sync.into() {
         let id = SyncId::Grpid(grpid);
diff --git a/src/receive_imf.rs b/src/receive_imf.rs
index cf330171a..2d15bda90 100644
--- a/src/receive_imf.rs
+++ b/src/receive_imf.rs
@@ -3571,6 +3571,9 @@ async fn apply_in_broadcast_changes(
                 info!(context, "No-op broadcast 'Member added' message (TRASH)");
                 msg = "".to_string();
             } else {
+                chat.id
+                    .add_encrypted_msg(context, mime_parser.timestamp_sent)
+                    .await?;
                 msg = stock_str::msg_add_member_local(context, ContactId::SELF, from_id).await;
             }