diff --git a/js/index.js b/js/index.js
index 489e53d..951d8e1 100644
--- a/js/index.js
+++ b/js/index.js
@@ -210,6 +210,7 @@ if (cookieBic !== "") {
 validateName(document.querySelector("#name input"));
 validateIban(document.querySelector("#iban input"));
 validateBic(document.querySelector("#bic input"));
+validateAmount(document.querySelector("#amount input"));
 validatePurpose(document.querySelector("#purpose input"));
 
 // generate qr code on first visit