diff --git a/crates/lavina-core/src/repo/room.rs b/crates/lavina-core/src/repo/room.rs
index 96b89f2..bd6f824 100644
--- a/crates/lavina-core/src/repo/room.rs
+++ b/crates/lavina-core/src/repo/room.rs
@@ -1,8 +1,29 @@
+use crate::player::PlayerConnection;
 use anyhow::Result;
 
 use crate::repo::Storage;
 
 impl Storage {
+    pub async fn is_room_member(&self, room_id: u32, player_id: u32) -> Result<bool> {
+        let mut executor = self.conn.lock().await;
+        let res: (bool,) = sqlx::query_as(
+            "
+            select
+                exists (
+                    select
+                        count(*)
+                    from
+                        memberships
+                    where
+                        user_id = ? and room_id = ?
+                );",
+        )
+        .bind(player_id)
+        .bind(room_id)
+        .fetch_one(&mut *executor)
+        .await?;
+        Ok(res.0)
+    }
     pub async fn add_room_member(&self, room_id: u32, player_id: u32) -> Result<()> {
         let mut executor = self.conn.lock().await;
         sqlx::query(
diff --git a/crates/lavina-core/src/room.rs b/crates/lavina-core/src/room.rs
index a5e2dab..8ad3b67 100644
--- a/crates/lavina-core/src/room.rs
+++ b/crates/lavina-core/src/room.rs
@@ -13,6 +13,7 @@ use crate::repo::Storage;
 /// Opaque room id
 #[derive(Debug, Clone, PartialEq, Eq, Hash, Serialize)]
 pub struct RoomId(Str);
+
 impl RoomId {
     pub fn from(str: impl Into<Str>) -> Result<RoomId> {
         let bytes = str.into();
@@ -35,6 +36,7 @@ impl RoomId {
 /// Shared data structure for storing metadata about rooms.
 #[derive(Clone)]
 pub struct RoomRegistry(Arc<AsyncRwLock<RoomRegistryInner>>);
+
 impl RoomRegistry {
     pub fn new(metrics: &mut MetricRegistry, storage: Storage) -> Result<RoomRegistry> {
         let metric_active_rooms = IntGauge::new("chat_rooms_active", "Number of alive room actors")?;
@@ -125,6 +127,7 @@ impl RoomRegistryInner {
 
 #[derive(Clone)]
 pub struct RoomHandle(Arc<AsyncRwLock<Room>>);
+
 impl RoomHandle {
     pub async fn subscribe(&self, player_id: &PlayerId, player_handle: PlayerHandle) {
         let mut lock = self.0.write().await;
@@ -136,7 +139,9 @@ impl RoomHandle {
         let mut lock = self.0.write().await;
         tracing::info!("Adding a new member to a room");
         let room_storage_id = lock.storage_id;
-        lock.storage.add_room_member(room_storage_id, player_storage_id).await.unwrap();
+        if !lock.storage.is_room_member(room_storage_id, player_storage_id).await.unwrap() {
+            lock.storage.add_room_member(room_storage_id, player_storage_id).await.unwrap();
+        }
         lock.members.insert(player_id.clone());
         let update = Updates::RoomJoined {
             room_id: lock.room_id.clone(),
@@ -207,6 +212,7 @@ struct Room {
     topic: Str,
     storage: Storage,
 }
+
 impl Room {
     async fn send_message(&mut self, author_id: &PlayerId, body: Str) -> Result<()> {
         tracing::info!("Adding a message to room");