diff --git a/controller/documentcontroller.php b/controller/documentcontroller.php
index f1314be6..a5d69da3 100644
--- a/controller/documentcontroller.php
+++ b/controller/documentcontroller.php
@@ -174,6 +174,8 @@ 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->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('*');