diff --git a/server/src/database/api.ts b/server/src/database/api.ts
index dfe6965..50b635f 100755
--- a/server/src/database/api.ts
+++ b/server/src/database/api.ts
@@ -17,15 +17,15 @@ export async function registerUser(email: string, name: string, group: Group) {
   return;
 }
 
-export async function getUserTeam(email: string): Promise<null | Group> {
+export async function getUserTeam(email: string): Promise<undefined | Group> {
   if (connection == null) {
-    return null;
+    return undefined;
   }
   const query = `select team from users where email=$1`
   const values = [email];
   const res = await connection.query(query, values);
   if (res.rows.length == 0) {
-    return null;
+    return undefined;
   } else {
     return res.rows[0].team;
   }
diff --git a/server/src/index.ts b/server/src/index.ts
index 7505f15..c884feb 100755
--- a/server/src/index.ts
+++ b/server/src/index.ts
@@ -152,7 +152,7 @@ io.on("connection", (socket) => {
         //   socket.data.group = 2;
         // }
         socket.data.group = await getUserTeam(unique_name);
-        if (socket.data.group == null) {
+        if (!socket.data.group) {
           socket.data.group = Math.random() > 0.5 ? 2 : 1;
         }
       } else {