diff --git a/src/Intervention/Image/AbstractEncoder.php b/src/Intervention/Image/AbstractEncoder.php
index 9cbf7dc4..afc8ecdb 100644
--- a/src/Intervention/Image/AbstractEncoder.php
+++ b/src/Intervention/Image/AbstractEncoder.php
@@ -135,6 +135,7 @@ abstract class AbstractEncoder
                 break;
 
             case 'ico':
+            case 'image/x-ico':
             case 'image/x-icon':
             case 'image/vnd.microsoft.icon':
                 $this->result = $this->processIco();