| Index: messageResponder.js | 
| =================================================================== | 
| --- a/messageResponder.js | 
| +++ b/messageResponder.js | 
| @@ -25,6 +25,7 @@ | 
| const {port} = require("messaging"); | 
| const {Prefs} = require("prefs"); | 
| + const {compareVersion} = require("coreUtils"); | 
| const {Utils} = require("utils"); | 
| const {FilterStorage} = require("filterStorage"); | 
| const {FilterNotifier} = require("filterNotifier"); | 
| @@ -175,7 +176,9 @@ | 
| if (message.what == "features") | 
| { | 
| return { | 
| - devToolsPanel: info.platform == "chromium" | 
| + devToolsPanel: info.platform == "chromium" || | 
| + info.application == "firefox" && | 
| + compareVersion(info.applicationVersion, "54") >= 0 | 
| }; | 
| } |