diff --git a/src/main.rs b/src/main.rs
index 4e38545..aacbb77 100644
--- a/src/main.rs
+++ b/src/main.rs
@@ -29,7 +29,7 @@ async fn handler(Query(request): Query<GenerateRequest>) -> Result<Json<Generate
     if request.secret != *API_SECRET {
         return Err(StatusCode::UNAUTHORIZED);
     }
-    if !request.email.contains('@') {
+    if !request.email.is_ascii() || !request.email.contains('@') {
         return Err(StatusCode::UNAUTHORIZED);
     }
     println!("{}", request.email);