diff --git a/packages/socket.io-adapter/lib/in-memory-adapter.ts b/packages/socket.io-adapter/lib/in-memory-adapter.ts
index cf178170e0..ee2a4d1a3f 100644
--- a/packages/socket.io-adapter/lib/in-memory-adapter.ts
+++ b/packages/socket.io-adapter/lib/in-memory-adapter.ts
@@ -300,7 +300,10 @@ export class Adapter extends EventEmitter {
    * @param opts - the filters to apply
    * @param rooms - the rooms to join
    */
-  public addSockets(opts: BroadcastOptions, rooms: Room[]): void {
+  public addSockets(
+    opts: BroadcastOptions,
+    rooms: Room[],
+  ): void | Promise<void> {
     this.apply(opts, (socket) => {
       socket.join(rooms);
     });
@@ -312,7 +315,10 @@ export class Adapter extends EventEmitter {
    * @param opts - the filters to apply
    * @param rooms - the rooms to leave
    */
-  public delSockets(opts: BroadcastOptions, rooms: Room[]): void {
+  public delSockets(
+    opts: BroadcastOptions,
+    rooms: Room[],
+  ): void | Promise<void> {
     this.apply(opts, (socket) => {
       rooms.forEach((room) => socket.leave(room));
     });
@@ -324,7 +330,10 @@ export class Adapter extends EventEmitter {
    * @param opts - the filters to apply
    * @param close - whether to close the underlying connection
    */
-  public disconnectSockets(opts: BroadcastOptions, close: boolean): void {
+  public disconnectSockets(
+    opts: BroadcastOptions,
+    close: boolean,
+  ): void | Promise<void> {
     this.apply(opts, (socket) => {
       socket.disconnect(close);
     });
diff --git a/packages/socket.io/lib/broadcast-operator.ts b/packages/socket.io/lib/broadcast-operator.ts
index ca7eccf2f4..ee32bb1ca6 100644
--- a/packages/socket.io/lib/broadcast-operator.ts
+++ b/packages/socket.io/lib/broadcast-operator.ts
@@ -413,8 +413,8 @@ export class BroadcastOperator<EmitEvents extends EventsMap, SocketData>
    *
    * @param room - a room, or an array of rooms
    */
-  public socketsJoin(room: Room | Room[]): void {
-    this.adapter.addSockets(
+  public socketsJoin(room: Room | Room[]): void | Promise<void> {
+    return this.adapter.addSockets(
       {
         rooms: this.rooms,
         except: this.exceptRooms,
@@ -438,8 +438,8 @@ export class BroadcastOperator<EmitEvents extends EventsMap, SocketData>
    *
    * @param room - a room, or an array of rooms
    */
-  public socketsLeave(room: Room | Room[]): void {
-    this.adapter.delSockets(
+  public socketsLeave(room: Room | Room[]): void | Promise<void> {
+    return this.adapter.delSockets(
       {
         rooms: this.rooms,
         except: this.exceptRooms,
@@ -463,8 +463,8 @@ export class BroadcastOperator<EmitEvents extends EventsMap, SocketData>
    *
    * @param close - whether to close the underlying connection
    */
-  public disconnectSockets(close: boolean = false): void {
-    this.adapter.disconnectSockets(
+  public disconnectSockets(close: boolean = false): void | Promise<void> {
+    return this.adapter.disconnectSockets(
       {
         rooms: this.rooms,
         except: this.exceptRooms,
@@ -554,7 +554,7 @@ export class RemoteSocket<EmitEvents extends EventsMap, SocketData>
    *
    * @param {String|Array} room - room or array of rooms
    */
-  public join(room: Room | Room[]): void {
+  public join(room: Room | Room[]): void | Promise<void> {
     return this.operator.socketsJoin(room);
   }
 
@@ -563,7 +563,7 @@ export class RemoteSocket<EmitEvents extends EventsMap, SocketData>
    *
    * @param {String} room
    */
-  public leave(room: Room): void {
+  public leave(room: Room): void | Promise<void> {
     return this.operator.socketsLeave(room);
   }