diff --git a/proxy/proxy.php b/proxy/proxy.php
index 0b13a09..684fad5 100644
--- a/proxy/proxy.php
+++ b/proxy/proxy.php
@@ -218,6 +218,7 @@ function civiproxy_sanitise($value, $type) {
     error_log("CiviProxy: unknown type '$type'. Ignored.");
     $value = '';
   }
+  return $value;
 }