diff --git a/classes/TokenBuilder.php b/classes/TokenBuilder.php
index 912c13dea92f5e622d6276fcb45138e2d502ae40..22d74f9c7fb28713e9a02a0aedc6765e9f1bc623 100644
--- a/classes/TokenBuilder.php
+++ b/classes/TokenBuilder.php
@@ -98,7 +98,7 @@ class TokenBuilder {
         if ($client->scopeAudienceMap !== null) {
             foreach ($tokenData->scope as $scope) {
                 if (array_key_exists($scope, $client->scopeAudienceMap)) {
-                    $audience = $client->scopeAudienceMap[$scope];
+                    $audience = ((array) $client->scopeAudienceMap)[$scope];
                     if (!in_array($audience, $audiences)) {
                         array_push($audiences, $audience);
                     }