diff --git a/etemplate/js/et2_widget_link.js b/etemplate/js/et2_widget_link.js
index b25bf5ce71..fb63f724e8 100644
--- a/etemplate/js/et2_widget_link.js
+++ b/etemplate/js/et2_widget_link.js
@@ -1360,7 +1360,7 @@ var et2_link_string = expose(et2_valueWidget.extend([et2_IDetachedDOM],
 	{
 		var base_url = egw.webserverUrl.match(/^\//,'ig')?egw(window).window.location.origin + egw.webserverUrl : egw.webserverUrl;
 		var mediaContent = [];
-		if (_value && typeof _value.type !='undefined' && _value.type.match(/video\/|audio\//,'ig'))
+		if (_value && typeof _value.type !='undefined' && _value.type.match(/video\//,'ig'))
 		{
 			mediaContent = [{
 					title: _value.id,
diff --git a/etemplate/js/et2_widget_vfs.js b/etemplate/js/et2_widget_vfs.js
index f9e1cc2fc0..b4f20ca145 100644
--- a/etemplate/js/et2_widget_vfs.js
+++ b/etemplate/js/et2_widget_vfs.js
@@ -341,7 +341,7 @@ var et2_vfsMime = expose(et2_valueWidget.extend([et2_IDetachedDOM],
 				mediaContent[0].download_href = mediaContent[0].href + '?download';
 			}
 		}
-		if (_value && _value.mime && _value.mime.match(/video\/|audio\//,'ig'))
+		if (_value && _value.mime && _value.mime.match(/video\//,'ig'))
 		{
 			mediaContent[0].thumbnail = this.egw().mime_icon(_value.mime, _value.path, undefined, _value.mtime);
 		}
diff --git a/etemplate/js/expose.js b/etemplate/js/expose.js
index 2f5d7b599b..914042b35e 100644
--- a/etemplate/js/expose.js
+++ b/etemplate/js/expose.js
@@ -48,7 +48,10 @@ function expose (widget)
 	};
 
 	// For filtering to only show things we can handle
-	var mime_regex = new RegExp(/(video\/)|(image\/:*(?!tif|x-xcf))|(audio\/)/);
+	var mime_regex = new RegExp(/(video\/(mp4|ogg|webm))|(image\/:*(?!tif|x-xcf|pdf))/);
+	
+	// IE only supports video/mp4 mime type
+	if (navigator.userAgent.match(/(MSIE|Trident)/)) mime_regex.compile(/(video\/mp4)|(image\/:*(?!tif|x-xcf|pdf))/);
 
 	// Only one gallery
 	var gallery = null;
diff --git a/phpgwapi/inc/class.html.inc.php b/phpgwapi/inc/class.html.inc.php
index 586d5fe8f5..7704c18947 100644
--- a/phpgwapi/inc/class.html.inc.php
+++ b/phpgwapi/inc/class.html.inc.php
@@ -1515,6 +1515,9 @@ egw_LAB.wait(function() {
 	 */
 	public static function safe_content_header(&$content, $path, &$mime='', &$length=0, $nocache=true, $force_download=true, $no_content_type=false)
 	{
+		// change old/aliased mime-types to new one, eg. image/pdf to application/pdf
+		$mime = mime_magic::fix_mime_type($mime);
+
 		// mitigate risk of serving javascript or css via webdav from our domain,
 		// which will get around same origin policy and CSP
 		list($type, $subtype) = explode('/', strtolower($mime));
diff --git a/phpgwapi/inc/class.mime_magic.inc.php b/phpgwapi/inc/class.mime_magic.inc.php
index 945d6c12c3..127f0ee645 100644
--- a/phpgwapi/inc/class.mime_magic.inc.php
+++ b/phpgwapi/inc/class.mime_magic.inc.php
@@ -123,6 +123,23 @@ class mime_magic
 		return $key;
 	}
 
+	/**
+	 * Fix old / aliased mime-types by returning valid/default mime-type
+	 *
+	 * @param string $_alias
+	 * @return string new type, of $alias, if there is no alias defined for it
+	 */
+	public static function fix_mime_type($_alias)
+	{
+		$alias = strtolower($_alias);
+
+		if (isset(self::$mime_alias_map[$alias]))
+		{
+			return self::$mime_alias_map[$alias];
+		}
+		return $alias;
+	}
+
 	/**
 	 * Uses variants of the UNIX "file" command to attempt to determine the
 	 * MIME type of an unknown file.
@@ -1671,6 +1688,7 @@ class mime_magic
 		'application/x-javascript' => 'application/javascript',
 		'application/x-troff' => 'text/troff',
 		'application/x-egroupware-etemplate' => 'application/xml',
+		'image/pdf' => 'application/pdf',
 	);
 
 	/**