diff --git a/src/helpers/sanitizeName.js b/src/helpers/sanitizeName.js
index 6409f829243101380a8fca26cd28d591443b8537..1ab3c48d38653222e3411ac9d710137acb84ea3b 100644
--- a/src/helpers/sanitizeName.js
+++ b/src/helpers/sanitizeName.js
@@ -22,6 +22,7 @@ const REPLACE_CHARS = {
  */
 function sanitizeLastname(lastname) {
   return lastname
+    .toLowerCase()
     .replace(/[âêîôûäëïöüéàèç]/g, match => REPLACE_CHARS[match])
     .trim()
 }