diff --git a/htdocs/helpers.php b/htdocs/helpers.php
index 3f04c83b68ba154b1a18d1cfd8676fe830b6a8cf..46716ed7696c679ccbebd9f0fff6e9eeb1a7a8d8 100644
--- a/htdocs/helpers.php
+++ b/htdocs/helpers.php
@@ -65,20 +65,24 @@ function isEmailDomainBlackListed($email): bool
 
 function sendInviteMail($to, $secret, $lang, ?string $referrer = null, ?string $shopLocation = null)
 {
-    $encoded_email = urlencode($to);
     $domain = getenv("DOMAIN");
     $signupURL = "https://$domain/signup/";
     if ($lang != "en") {
         $signupURL .= "$lang/";
     }
-    $signupURL .= "register?authmail=$encoded_email&authsecret=$secret";
+    $signupURL .= "register?";
+    $query = [
+        "authmail"=> $to,
+        "authsecret"=>$secret
+        ];
     if ($referrer != null) {
-        $signupURL .= "&ref=$referrer";
+        $query["ref"] = $referrer;
     }
     if ($shopLocation) {
-        $signupURL .= "&shop=$shopLocation";
+        $query["shop"] = $shopLocation;
     }
     $SENDGRID_API_KEY = getenv("SENDGRID_API_KEY");
+    $signupURL = $signupURL . http_build_query($query);
     if (!empty($SENDGRID_API_KEY)) {
         return sendInviteMailWithSendGrid($to, $signupURL);
     }