diff --git a/crates/buzz-db/src/store/channel.rs b/crates/buzz-db/src/store/channel.rs
index 5e89b1101b..1ad48ca5c5 100644
--- a/crates/buzz-db/src/store/channel.rs
+++ b/crates/buzz-db/src/store/channel.rs
@@ -150,6 +150,9 @@ pub async fn create_channel(
         INSERT INTO channel_members (community_id, channel_id, pubkey, role, invited_by)
         VALUES ($1, $2, $3, 'owner', $4)
         ON CONFLICT (community_id, channel_id, pubkey) DO UPDATE SET
+            -- A rejoin starts caught up: unread counts from here.
+            joined_at = CASE WHEN channel_members.removed_at IS NULL
+                THEN channel_members.joined_at ELSE now() END,
             removed_at = NULL,
             removed_by = NULL,
             role = EXCLUDED.role
@@ -249,6 +252,9 @@ pub async fn create_channel_with_id(
             INSERT INTO channel_members (community_id, channel_id, pubkey, role, invited_by)
             VALUES ($1, $2, $3, 'owner', $4)
             ON CONFLICT (community_id, channel_id, pubkey) DO UPDATE SET
+                -- A rejoin starts caught up: unread counts from here.
+                joined_at = CASE WHEN channel_members.removed_at IS NULL
+                    THEN channel_members.joined_at ELSE now() END,
                 removed_at = NULL,
                 removed_by = NULL,
                 role = EXCLUDED.role
diff --git a/crates/buzz-db/src/store/channel_members.rs b/crates/buzz-db/src/store/channel_members.rs
index c369bf59a0..fc4967e601 100644
--- a/crates/buzz-db/src/store/channel_members.rs
+++ b/crates/buzz-db/src/store/channel_members.rs
@@ -257,6 +257,9 @@ pub async fn insert_auto_membership_in_transaction(
         INSERT INTO channel_members (community_id, channel_id, pubkey, role, invited_by)
         VALUES ($1, $2, $3, 'member'::member_role, $4)
         ON CONFLICT (community_id, channel_id, pubkey) DO UPDATE SET
+            -- A rejoin starts caught up: unread counts from here.
+            joined_at = CASE WHEN channel_members.removed_at IS NULL
+                THEN channel_members.joined_at ELSE now() END,
             removed_at = NULL,
             removed_by = NULL,
             role = EXCLUDED.role
@@ -601,6 +604,9 @@ pub async fn add_member(
         INSERT INTO channel_members (community_id, channel_id, pubkey, role, invited_by)
         VALUES ($1, $2, $3, $4::member_role, $5)
         ON CONFLICT (community_id, channel_id, pubkey) DO UPDATE SET
+            -- A rejoin starts caught up: unread counts from here.
+            joined_at = CASE WHEN channel_members.removed_at IS NULL
+                THEN channel_members.joined_at ELSE now() END,
             removed_at = NULL,
             removed_by = NULL,
             role = EXCLUDED.role
diff --git a/crates/buzz-db/src/store/dm.rs b/crates/buzz-db/src/store/dm.rs
index 89e4a0e522..34693bb716 100644
--- a/crates/buzz-db/src/store/dm.rs
+++ b/crates/buzz-db/src/store/dm.rs
@@ -187,6 +187,9 @@ pub async fn create_dm(
             INSERT INTO channel_members (community_id, channel_id, pubkey, role, invited_by)
             VALUES ($1, $2, $3, 'member', $4)
             ON CONFLICT (community_id, channel_id, pubkey) DO UPDATE SET
+                -- A rejoin starts caught up: unread counts from here.
+                joined_at = CASE WHEN channel_members.removed_at IS NULL
+                    THEN channel_members.joined_at ELSE now() END,
                 removed_at = NULL,
                 removed_by = NULL,
                 role = EXCLUDED.role
diff --git a/crates/buzz-db/src/store/personal_read/postgres_tests.rs b/crates/buzz-db/src/store/personal_read/postgres_tests.rs
index 705a714226..41b16a7376 100644
--- a/crates/buzz-db/src/store/personal_read/postgres_tests.rs
+++ b/crates/buzz-db/src/store/personal_read/postgres_tests.rs
@@ -315,6 +315,55 @@ async fn joining_starts_caught_up_and_counts_only_what_arrives_after() {
     );
 }
 
+#[tokio::test]
+#[ignore = "requires Postgres"]
+async fn rejoining_starts_caught_up_again() {
+    let (db, pool, community, channel, owner, _) = fixture().await;
+    let member = Keys::generate();
+    let pk = member.public_key().to_bytes();
+    start(&pool, community, &member).await;
+    db.add_member(community, channel, &pk, MemberRole::Member, None)
+        .await
+        .unwrap();
+    sqlx::query(
+        "UPDATE channel_members SET joined_at=now()-interval '1 hour'
+         WHERE community_id=$1 AND channel_id=$2 AND pubkey=$3",
+    )
+    .bind(community.as_uuid())
+    .bind(channel)
+    .bind(pk.as_slice())
+    .execute(&pool)
+    .await
+    .unwrap();
+    db.remove_member(community, channel, &pk, &pk)
+        .await
+        .unwrap();
+    let away = post(&db, community, channel, &Keys::generate(), now(), vec![]).await;
+    // Re-adding an active member (a role change) must not move the position.
+    let owner_pk = owner.public_key().to_bytes();
+    db.add_member(
+        community,
+        channel,
+        &owner_pk,
+        MemberRole::Owner,
+        Some(&owner_pk),
+    )
+    .await
+    .unwrap();
+    assert_eq!(sidebar(&db, community, &owner).await.unread, 2);
+    db.add_member(community, channel, &pk, MemberRole::Member, None)
+        .await
+        .unwrap();
+    let row = sidebar(&db, community, &member).await;
+    assert_eq!(row.unread, 0, "messages from while away are read");
+    assert_eq!(
+        status(&db, community, &member, channel, None, &[&away]).await,
+        ["read"]
+    );
+    post(&db, community, channel, &Keys::generate(), now(), vec![]).await;
+    assert_eq!(sidebar(&db, community, &member).await.unread, 1);
+}
+
 #[tokio::test]
 #[ignore = "requires Postgres"]
 async fn read_state_starts_caught_up_at_the_first_intent() {