diff --git a/module/VuFind/src/VuFind/ILS/Driver/KohaILSDI.php b/module/VuFind/src/VuFind/ILS/Driver/KohaILSDI.php
index 1e3f82a19ffb08a895cf8301768d37e3eb3fe530..c3a9c4e7266239248ca624517b5cd97167f655c4 100644
--- a/module/VuFind/src/VuFind/ILS/Driver/KohaILSDI.php
+++ b/module/VuFind/src/VuFind/ILS/Driver/KohaILSDI.php
@@ -1603,7 +1603,7 @@ class KohaILSDI extends \VuFind\ILS\Driver\AbstractBase implements
         //       . "&password=" . $password
         // );
         $idObj = $this->makeRequest(
-            "LookupPatron" . "&id=" . $username
+            "LookupPatron" . "&id=" . urlencode($username)
             . "&id_type=userid"
         );