diff --git a/src/users/user.entity.ts b/src/users/user.entity.ts
index ca753c7bd..33e26114d 100644
--- a/src/users/user.entity.ts
+++ b/src/users/user.entity.ts
@@ -23,7 +23,9 @@ export class User {
   @PrimaryGeneratedColumn('uuid')
   id: string;
 
-  @Column()
+  @Column({
+    unique: true,
+  })
   userName: string;
 
   @Column()