diff --git a/controller/documentcontroller.php b/controller/documentcontroller.php
index ad85f728..4f3d5b09 100644
--- a/controller/documentcontroller.php
+++ b/controller/documentcontroller.php
@@ -344,7 +344,7 @@ class DocumentController extends Controller {
 		$policy = new ContentSecurityPolicy();
 		$policy->addAllowedScriptDomain('\'self\' http://ajax.googleapis.com/ajax/libs/jquery/2.1.0/jquery.min.js http://cdnjs.cloudflare.com/ajax/libs/jquery-mousewheel/3.1.12/jquery.mousewheel.min.js \'unsafe-eval\' ' . $wopiRemote);
 		/* frame-src is deprecated on Firefox, but Safari wants it! */
-		$policy->addAllowedFrameDomain('\'self\' http://ajax.googleapis.com/ajax/libs/jquery/2.1.0/jquery.min.js http://cdnjs.cloudflare.com/ajax/libs/jquery-mousewheel/3.1.12/jquery.mousewheel.min.js \'unsafe-eval\' ' . $wopiRemote);
+		$policy->addAllowedFrameDomain('\'self\' http://ajax.googleapis.com/ajax/libs/jquery/2.1.0/jquery.min.js http://cdnjs.cloudflare.com/ajax/libs/jquery-mousewheel/3.1.12/jquery.mousewheel.min.js \'unsafe-eval\' ' . $wopiRemote . ' blob:');
 		$policy->addAllowedChildSrcDomain('\'self\' http://ajax.googleapis.com/ajax/libs/jquery/2.1.0/jquery.min.js http://cdnjs.cloudflare.com/ajax/libs/jquery-mousewheel/3.1.12/jquery.mousewheel.min.js \'unsafe-eval\' ' . $wopiRemote);
 		$policy->addAllowedConnectDomain($webSocket);
 		$policy->addAllowedImageDomain('*');