diff --git a/lib/less-browser/add-default-options.js b/lib/less-browser/add-default-options.js
index 6c0fb7a2..c13bada7 100644
--- a/lib/less-browser/add-default-options.js
+++ b/lib/less-browser/add-default-options.js
@@ -7,7 +7,7 @@ module.exports = function(window, options) {
     addDataAttr(options, browser.currentScript(window));
 
     if (options.isFileProtocol === undefined) {
-        options.isFileProtocol = /^(file|chrome(-extension)?|resource|qrc|app):/.test(window.location.protocol);
+        options.isFileProtocol = /^(file|(chrome|safari)(-extension)?|resource|qrc|app):/.test(window.location.protocol);
     }
 
     // Load styles asynchronously (default: false)