diff --git a/server/lib/Lobby.js b/server/lib/Lobby.js
index b5d9fb6..75cae49 100644
--- a/server/lib/Lobby.js
+++ b/server/lib/Lobby.js
@@ -14,7 +14,7 @@ class Lobby extends EventEmitter
 		// Closed flag.
 		this._closed = false;
 
-		this._peers = new Map();
+		this._peers = {};
 	}
 
 	close()
@@ -23,27 +23,28 @@ class Lobby extends EventEmitter
 
 		this._closed = true;
 
-		this._peers.forEach((peer) =>
+		// Close the peers.
+		for (const peer in this._peers)
 		{
 			if (!peer.closed)
 				peer.close();
-		});
+		}
 
-		this._peers.clear();
+		this._peers = null;
 	}
 
 	checkEmpty()
 	{
 		logger.info('checkEmpty()');
 		
-		return this._peers.size === 0;
+		return Object.keys(this._peers).length === 0;
 	}
 
 	peerList()
 	{
 		logger.info('peerList()');
 
-		return Array.from(this._peers.values()).map((peer) =>
+		return Object.values(this._peers).map((peer) =>
 			({
 				peerId      : peer.id,
 				displayName : peer.displayName 
@@ -52,25 +53,25 @@ class Lobby extends EventEmitter
 
 	hasPeer(peerId)
 	{
-		return this._peers.has(peerId);
+		return this._peers[peerId] != null;
 	}
 
 	promoteAllPeers()
 	{
 		logger.info('promoteAllPeers()');
 
-		this._peers.forEach((peer) =>
+		for (const peer in this._peers)
 		{
 			if (peer.socket)
 				this.promotePeer(peer.id);
-		});
+		}
 	}
 
 	promotePeer(peerId)
 	{
 		logger.info('promotePeer() [peer:"%s"]', peerId);
 
-		const peer = this._peers.get(peerId);
+		const peer = this._peers[peerId];
 
 		if (peer)
 		{
@@ -87,7 +88,7 @@ class Lobby extends EventEmitter
 			peer.closeHandler = null;
 
 			this.emit('promotePeer', peer);
-			this._peers.delete(peerId);
+			delete this._peers[peerId];
 		}
 	}
 
@@ -146,7 +147,7 @@ class Lobby extends EventEmitter
 
 			this.emit('peerClosed', peer);
 
-			this._peers.delete(peer.id);
+			delete this._peers[peer.id];
 
 			if (this.checkEmpty())
 				this.emit('lobbyEmpty');
@@ -154,7 +155,7 @@ class Lobby extends EventEmitter
 
 		this._notification(peer.socket, 'enteredLobby');
 
-		this._peers.set(peer.id, peer);
+		this._peers[peer.id] = peer;
 
 		peer.on('gotRole', peer.gotRoleHandler);
 		peer.on('displayNameChanged', peer.displayNameChangeHandler);
diff --git a/server/lib/Room.js b/server/lib/Room.js
index 1fed90b..af5bea5 100644
--- a/server/lib/Room.js
+++ b/server/lib/Room.js
@@ -100,11 +100,8 @@ class Room extends EventEmitter
 		// Close the peers.
 		for (const peer in this._peers)
 		{
-			if (Object.prototype.hasOwnProperty.call(this._peers, peer))
-			{
-				if (!peer.closed)
-					peer.close();
-			}
+			if (!peer.closed)
+				peer.close();
 		}
 
 		this._peers = null;
@@ -313,7 +310,6 @@ class Room extends EventEmitter
 		}, 10000);
 	}
 
-	// checks both room and lobby
 	checkEmpty()
 	{
 		return Object.keys(this._peers).length === 0;
@@ -333,12 +329,8 @@ class Room extends EventEmitter
 	{
 		peer.socket.join(this._roomId);
 
-		const index = this._lastN.indexOf(peer.id);
-
-		if (index === -1) // We don't have this peer, add to end
-		{
-			this._lastN.push(peer.id);
-		}
+		// If we don't have this peer, add to end
+		!this._lastN.includes(peer.id) && this._lastN.push(peer.id);
 
 		this._peers[peer.id] = peer;
 
@@ -372,25 +364,17 @@ class Room extends EventEmitter
 
 			// If the Peer was joined, notify all Peers.
 			if (peer.joined)
-			{
 				this._notification(peer.socket, 'peerClosed', { peerId: peer.id }, true);
-			}
 
-			const index = this._lastN.indexOf(peer.id);
-
-			if (index > -1) // We have this peer in the list, remove
-			{
-				this._lastN.splice(index, 1);
-			}
+			// Remove from lastN
+			this._lastN = this._lastN.filter((id) => id !== peer.id);
 
 			delete this._peers[peer.id];
 
 			// If this is the last Peer in the room and
 			// lobby is empty, close the room after a while.
 			if (this.checkEmpty() && this._lobby.checkEmpty())
-			{
 				this.selfDestructCountdown();
-			}
 		});
 
 		peer.on('displayNameChanged', ({ oldDisplayName }) =>