diff --git a/module/VuFind/src/VuFind/ILS/Driver/PAIA.php b/module/VuFind/src/VuFind/ILS/Driver/PAIA.php
index 0994fa2596afc765ca7c83e78902bee0c80e7a57..062043d9344acdcb3116f29818637cb71a52c10e 100644
--- a/module/VuFind/src/VuFind/ILS/Driver/PAIA.php
+++ b/module/VuFind/src/VuFind/ILS/Driver/PAIA.php
@@ -335,7 +335,9 @@ class PAIA extends DAIA
                     isset($array_response['error_description'])
                         ? $array_response['error_description'] : ' '
             ];
-        } elseif ($array_response['patron'] === $post_data['patron']) {
+        } elseif (isset($array_response['patron'])
+            && $array_response['patron'] === $post_data['patron']
+        ) {
             // on success patron_id is returned
             $details = [
                 'success' => true,