diff --git a/src/channelManager.ts b/src/channelManager.ts
index 03f9515..a6100b1 100644
--- a/src/channelManager.ts
+++ b/src/channelManager.ts
@@ -57,7 +57,9 @@ class ChannelManager {
 
   createByChannelType(data: any) {
     try {
-      logger.accessLog.info(`attempting to create channel of type ${data.channel_type}, channel id: ${data.channel}...`);
+      logger.accessLog.info(
+        `attempting to create channel of type ${data.channel_type}, channel id: ${data.channel}...`
+      );
 
       if (data.channel_type === 'public') {
         return new PublicChannel(data.channel);
diff --git a/src/clientManager.ts b/src/clientManager.ts
index 91437f2..8475ba1 100644
--- a/src/clientManager.ts
+++ b/src/clientManager.ts
@@ -27,7 +27,7 @@ class ClientManager {
   }
 
   clientsOfType(client_type: string) {
-    let result: PublicClient[]|PrivateClient[]|CustomClient[] = [];
+    const result: PublicClient[]|PrivateClient[]|CustomClient[] = [];
 
     for (const client of this.clients) {
       if (client.type() === client_type) {
diff --git a/src/routes.ts b/src/routes.ts
index 6fed84d..255cf9b 100644
--- a/src/routes.ts
+++ b/src/routes.ts
@@ -3,7 +3,7 @@ import * as express from 'express';
 
 const app = require('./config/app');
 const corsOptions = {
-  origin: (origin: string, callback: Function) => {
+  origin: (origin: string, callback: (error: any, success?: boolean) => void) => {
     if (app.whitelist.indexOf(origin) !== -1) {
       callback(null, true);
     } else {
diff --git a/src/server.ts b/src/server.ts
index 1e9fa9c..562cae6 100755
--- a/src/server.ts
+++ b/src/server.ts
@@ -26,6 +26,7 @@ function connectionManager() {
       ws.close();
     } else {
       const data = result.data;
+      var client: PublicClient|PrivateClient|CustomClient|null;
       logger.accessLog.info(`Client Connected: ${data.user_id}`);
 
       if (!channelManager.channelExists(data.channel)) {
@@ -33,13 +34,13 @@ function connectionManager() {
       }
 
       if (clientManager.clientExists(data.user_id)) {
-        var client: PublicClient|PrivateClient|CustomClient|null = clientManager.getClient(data.user_id);
+        client = clientManager.getClient(data.user_id);
 
         if (client != null) {
           client.replaceWebSocket(ws);
         }
       } else {
-        var client: PublicClient|PrivateClient|CustomClient|null = clientManager.addClient(data, channelManager, ws);
+        client = clientManager.addClient(data, channelManager, ws);
       }
 
       if (client != null) {