diff --git a/bridges/YoutubeBridge.php b/bridges/YoutubeBridge.php
index abbb0d97..3ead3e82 100644
--- a/bridges/YoutubeBridge.php
+++ b/bridges/YoutubeBridge.php
@@ -65,6 +65,7 @@ class YoutubeBridge extends BridgeAbstract{
             $item->uri = 'https://www.youtube.com'.$element->find('a',0)->href;
             $item->thumbnailUri = 'https:'.$element->find('img',0)->src;
             $item->attachment = htmlspecialchars($video);
+            $item->attachmentCodec = "video/mp4";
             $item->title = trim($element->find('h3',0)->plaintext);
             $item->content = '<a href="' . $item->uri . '"><img src="' . $item->thumbnailUri . '" /></a><br><a href="' . $item->uri . '">' . $item->title . '</a>';
             $this->items[] = $item;
diff --git a/formats/AtomFormat.php b/formats/AtomFormat.php
index 7f71e771..b9a69b9a 100644
--- a/formats/AtomFormat.php
+++ b/formats/AtomFormat.php
@@ -26,6 +26,7 @@ class AtomFormat extends FormatAbstract{
             $entryTitle = is_null($data->title) ? '' : $data->title;
             $entryUri = is_null($data->uri) ? '' : $data->uri;
             $entryAttachment = is_null($data->attachment) ? '' : $data->attachment;
+            $entryAttachmentCodec = is_null($data->attachmentCodec) ? '' : $data->attachmentCodec;
             $entryTimestamp = is_null($data->timestamp) ? date(DATE_ATOM, 0) : date(DATE_ATOM, $data->timestamp);
             $timestamps[] = (int)$entryTimestamp;
             // We prevent content from closing the CDATA too early.
@@ -43,7 +44,7 @@ class AtomFormat extends FormatAbstract{
         <id>{$entryUri}</id>
         <updated>{$entryTimestamp}</updated>
         <content type="html">{$entryContent}</content>
-        <link rel="enclosure" href="{$entryAttachment}" />
+        <link rel="enclosure" href="{$entryAttachment}" type="{$entryAttachmentCodec}" />
     </entry>
 
 EOD;