diff --git a/apps/files/js/filelist.js b/apps/files/js/filelist.js
index 35fbdeecd3..550c10dba3 100644
--- a/apps/files/js/filelist.js
+++ b/apps/files/js/filelist.js
@@ -145,7 +145,7 @@ window.FileList={
 		if (loading) {
 			imgurl = OC.imagePath('core', 'loading.gif');
 		} else {
-			imgurl = OC.imagePath('core', 'filetypes/file.png');
+			imgurl = OC.imagePath('core', 'filetypes/file');
 		}
 		var tr = this.createRow(
 			'file',
@@ -173,7 +173,7 @@ window.FileList={
 		var tr = this.createRow(
 			'dir',
 			name,
-			OC.imagePath('core', 'filetypes/folder.png'),
+			OC.imagePath('core', 'filetypes/folder'),
 			OC.linkTo('files', 'index.php')+"?dir="+ encodeURIComponent($('#dir').val()+'/'+name).replace(/%2F/g, '/'),
 			size,
 			lastModified,
@@ -969,7 +969,7 @@ $(document).ready(function() {
 				uploadtext.attr('currentUploads', currentUploads);
 				var translatedText = n('files', 'Uploading %n file', 'Uploading %n files', currentUploads);
 				if (currentUploads === 0) {
-					var img = OC.imagePath('core', 'filetypes/folder.png');
+					var img = OC.imagePath('core', 'filetypes/folder');
 					data.context.find('td.filename').attr('style','background-image:url('+img+')');
 					uploadtext.text(translatedText);
 					uploadtext.hide();
@@ -1029,7 +1029,7 @@ $(document).ready(function() {
 		if (data.errorThrown === 'abort') {
 			//cleanup uploading to a dir
 			var uploadtext = $('tr .uploadtext');
-			var img = OC.imagePath('core', 'filetypes/folder.png');
+			var img = OC.imagePath('core', 'filetypes/folder');
 			uploadtext.parents('td.filename').attr('style','background-image:url('+img+')');
 			uploadtext.fadeOut();
 			uploadtext.attr('currentUploads', 0);
@@ -1042,7 +1042,7 @@ $(document).ready(function() {
 		if (data.errorThrown === 'abort') {
 			//cleanup uploading to a dir
 			var uploadtext = $('tr .uploadtext');
-			var img = OC.imagePath('core', 'filetypes/folder.png');
+			var img = OC.imagePath('core', 'filetypes/folder');
 			uploadtext.parents('td.filename').attr('style','background-image:url('+img+')');
 			uploadtext.fadeOut();
 			uploadtext.attr('currentUploads', 0);
diff --git a/apps/files/js/files.js b/apps/files/js/files.js
index fbac601f67..f454612070 100644
--- a/apps/files/js/files.js
+++ b/apps/files/js/files.js
@@ -734,6 +734,9 @@ Files.getMimeIcon = function(mime, ready) {
 		ready(Files.getMimeIcon.cache[mime]);
 	} else {
 		$.get( OC.filePath('files','ajax','mimeicon.php'), {mime: mime}, function(path) {
+			if(SVGSupport()){
+				path = path.substr(0, path.length-4) + '.svg';
+			}
 			Files.getMimeIcon.cache[mime]=path;
 			ready(Files.getMimeIcon.cache[mime]);
 		});
@@ -783,13 +786,16 @@ Files.lazyLoadPreview = function(path, mime, ready, width, height, etag) {
 		}
 		previewURL = previewURL.replace('(', '%28');
 		previewURL = previewURL.replace(')', '%29');
+		previewURL += '&forceIcon=0';
 
 		// preload image to prevent delay
 		// this will make the browser cache the image
 		var img = new Image();
 		img.onload = function(){
-			//set preview thumbnail URL
-			ready(previewURL);
+			// if loading the preview image failed (no preview for the mimetype) then img.width will < 5
+			if (img.width > 5) {
+				ready(previewURL);
+			}
 		}
 		img.src = previewURL;
 	});
diff --git a/apps/files/lib/helper.php b/apps/files/lib/helper.php
index ac8a2ad320..b9e41a352b 100644
--- a/apps/files/lib/helper.php
+++ b/apps/files/lib/helper.php
@@ -22,6 +22,7 @@ class Helper
 	public static function determineIcon($file) {
 		if($file['type'] === 'dir') {
 			$dir = $file['directory'];
+			$icon = \OC_Helper::mimetypeIcon('dir');
 			$absPath = \OC\Files\Filesystem::getView()->getAbsolutePath($dir.'/'.$file['name']);
 			$mount = \OC\Files\Filesystem::getMountManager()->find($absPath);
 			if (!is_null($mount)) {
@@ -29,21 +30,22 @@ class Helper
 				if (!is_null($sid)) {
 					$sid = explode(':', $sid);
 					if ($sid[0] === 'shared') {
-						return \OC_Helper::mimetypeIcon('dir-shared');
+						$icon = \OC_Helper::mimetypeIcon('dir-shared');
 					}
 					if ($sid[0] !== 'local' and $sid[0] !== 'home') {
-						return \OC_Helper::mimetypeIcon('dir-external');
+						$icon = \OC_Helper::mimetypeIcon('dir-external');
 					}
 				}
 			}
-			return \OC_Helper::mimetypeIcon('dir');
+		}else{
+			if($file['isPreviewAvailable']) {
+				$pathForPreview = $file['directory'] . '/' . $file['name'];
+				return \OC_Helper::previewIcon($pathForPreview) . '&c=' . $file['etag'];
+			}
+			$icon = \OC_Helper::mimetypeIcon($file['mimetype']);
 		}
 
-		if($file['isPreviewAvailable']) {
-			$pathForPreview = $file['directory'] . '/' . $file['name'];
-			return \OC_Helper::previewIcon($pathForPreview) . '&c=' . $file['etag'];
-		}
-		return \OC_Helper::mimetypeIcon($file['mimetype']);
+		return substr($icon, 0, -3) . 'svg';
 	}
 
 	/**
diff --git a/apps/files/tests/ajax_rename.php b/apps/files/tests/ajax_rename.php
index a1a5c8983b..e53c0fb3dd 100644
--- a/apps/files/tests/ajax_rename.php
+++ b/apps/files/tests/ajax_rename.php
@@ -110,7 +110,9 @@ class Test_OC_Files_App_Rename extends \PHPUnit_Framework_TestCase {
 		$this->assertEquals('/test', $result['data']['directory']);
 		$this->assertEquals(18, $result['data']['size']);
 		$this->assertEquals('httpd/unix-directory', $result['data']['mime']);
-		$this->assertEquals(\OC_Helper::mimetypeIcon('dir'), $result['data']['icon']);
+		$icon = \OC_Helper::mimetypeIcon('dir');
+		$icon = substr($icon, 0, -3) . 'svg';
+		$this->assertEquals($icon, $result['data']['icon']);
 		$this->assertFalse($result['data']['isPreviewAvailable']);
 	}
 
@@ -165,7 +167,9 @@ class Test_OC_Files_App_Rename extends \PHPUnit_Framework_TestCase {
 		$this->assertEquals(18, $result['data']['size']);
 		$this->assertEquals('httpd/unix-directory', $result['data']['mime']);
 		$this->assertEquals('abcdef', $result['data']['etag']);
-		$this->assertEquals(\OC_Helper::mimetypeIcon('dir'), $result['data']['icon']);
+		$icon = \OC_Helper::mimetypeIcon('dir');
+		$icon = substr($icon, 0, -3) . 'svg';
+		$this->assertEquals($icon, $result['data']['icon']);
 		$this->assertFalse($result['data']['isPreviewAvailable']);
 	}
 
diff --git a/apps/files_sharing/public.php b/apps/files_sharing/public.php
index e7a5f5024b..fe61dd4d5a 100644
--- a/apps/files_sharing/public.php
+++ b/apps/files_sharing/public.php
@@ -32,7 +32,8 @@ function determineIcon($file, $sharingRoot, $sharingToken) {
 	if($file['isPreviewAvailable']) {
 		return OCP\publicPreview_icon($relativePath, $sharingToken) . '&c=' . $file['etag'];
 	}
-	return OCP\mimetype_icon($file['mimetype']);
+	$icon = OCP\mimetype_icon($file['mimetype']);
+	return substr($icon, 0, -3) . 'svg';
 }
 
 if (isset($_GET['t'])) {
diff --git a/core/ajax/preview.php b/core/ajax/preview.php
index a1267d6f5c..526719e8a1 100644
--- a/core/ajax/preview.php
+++ b/core/ajax/preview.php
@@ -7,34 +7,39 @@
  */
 \OC_Util::checkLoggedIn();
 
-$file = array_key_exists('file', $_GET) ? (string) $_GET['file'] : '';
-$maxX = array_key_exists('x', $_GET) ? (int) $_GET['x'] : '36';
-$maxY = array_key_exists('y', $_GET) ? (int) $_GET['y'] : '36';
-$scalingUp = array_key_exists('scalingup', $_GET) ? (bool) $_GET['scalingup'] : true;
+$file = array_key_exists('file', $_GET) ? (string)$_GET['file'] : '';
+$maxX = array_key_exists('x', $_GET) ? (int)$_GET['x'] : '36';
+$maxY = array_key_exists('y', $_GET) ? (int)$_GET['y'] : '36';
+$scalingUp = array_key_exists('scalingup', $_GET) ? (bool)$_GET['scalingup'] : true;
+$always = array_key_exists('forceIcon', $_GET) ? (bool)$_GET['forceIcon'] : true;
 
-if($file === '') {
+if ($file === '') {
 	//400 Bad Request
 	\OC_Response::setStatus(400);
 	\OC_Log::write('core-preview', 'No file parameter was passed', \OC_Log::DEBUG);
 	exit;
 }
 
-if($maxX === 0 || $maxY === 0) {
+if ($maxX === 0 || $maxY === 0) {
 	//400 Bad Request
 	\OC_Response::setStatus(400);
 	\OC_Log::write('core-preview', 'x and/or y set to 0', \OC_Log::DEBUG);
 	exit;
 }
 
-try{
+try {
 	$preview = new \OC\Preview(\OC_User::getUser(), 'files');
-	$preview->setFile($file);
-	$preview->setMaxX($maxX);
-	$preview->setMaxY($maxY);
-	$preview->setScalingUp($scalingUp);
+	if (!$always and !$preview->isMimeSupported(\OC\Files\Filesystem::getMimeType($file))) {
+		\OC_Response::setStatus(404);
+	} else {
+		$preview->setFile($file);
+		$preview->setMaxX($maxX);
+		$preview->setMaxY($maxY);
+		$preview->setScalingUp($scalingUp);
+	}
 
 	$preview->show();
-}catch(\Exception $e) {
+} catch (\Exception $e) {
 	\OC_Response::setStatus(500);
 	\OC_Log::write('core', $e->getmessage(), \OC_Log::DEBUG);
-}
\ No newline at end of file
+}