diff --git a/username_generator/src/generator.ts b/username_generator/src/generator.ts
index 6104774..1a9ea29 100644
--- a/username_generator/src/generator.ts
+++ b/username_generator/src/generator.ts
@@ -7,7 +7,7 @@ export const lastNames = _lastNames as Lastnames;
 
 export interface Firstname {
     firstname: string;
-    sexe?: number;
+    sexe: number;
     occurrences: number;
 }