diff --git a/system/src/Grav/Common/Page/Media.php b/system/src/Grav/Common/Page/Media.php
index b452f4924..b8aba4351 100644
--- a/system/src/Grav/Common/Page/Media.php
+++ b/system/src/Grav/Common/Page/Media.php
@@ -97,6 +97,10 @@ class Media extends Getters
 
             $alternatives = $medium->getAlternatives();
 
+            if (empty($alternatives)) {
+                continue;
+            }
+
             $max = max(array_keys($alternatives));
 
             for ($i=2; $i < $max; $i++) {