diff --git a/apps.json b/apps.json
index 90dc1d941..c0088760f 100644
--- a/apps.json
+++ b/apps.json
@@ -16,7 +16,7 @@
   {
     "id": "boot",
     "name": "Bootloader",
-    "version": "0.39",
+    "version": "0.40",
     "description": "This is needed by Bangle.js to automatically load the clock, menu, widgets and settings",
     "icon": "bootloader.png",
     "type": "bootloader",
diff --git a/apps/boot/ChangeLog b/apps/boot/ChangeLog
index 5c929421b..d6619822b 100644
--- a/apps/boot/ChangeLog
+++ b/apps/boot/ChangeLog
@@ -43,3 +43,4 @@
 0.37: Remove Quiet Mode settings: now handled by Quiet Mode Schedule app
 0.38: Option to log to file if settings.log==2
 0.39: Fix passkey support (fix https://github.com/espruino/Espruino/issues/2035)
+0.40: Bootloader now rebuilds for new firmware versions
diff --git a/apps/boot/bootupdate.js b/apps/boot/bootupdate.js
index e338d9020..664d64ee7 100644
--- a/apps/boot/bootupdate.js
+++ b/apps/boot/bootupdate.js
@@ -6,11 +6,11 @@ var s = require('Storage').readJSON('setting.json',1)||{};
 var BANGLEJS2 = process.env.HWVERSION==2; // Is Bangle.js 2
 var boot = "";
 if (require('Storage').hash) { // new in 2v11 - helps ensure files haven't changed
-  var CRC = E.CRC32(require('Storage').read('setting.json'))+require('Storage').hash(/\.boot\.js/);
-  boot += `if (E.CRC32(require('Storage').read('setting.json'))+require('Storage').hash(/\\.boot\\.js/)!=${CRC})`;
+  var CRC = E.CRC32(require('Storage').read('setting.json'))+require('Storage').hash(/\.boot\.js/)+E.CRC32(process.env.GIT_COMMIT);
+  boot += `if (E.CRC32(require('Storage').read('setting.json'))+require('Storage').hash(/\\.boot\\.js/)+E.CRC32(process.env.GIT_COMMIT)!=${CRC})`;
 } else {
-  var CRC = E.CRC32(require('Storage').read('setting.json'))+E.CRC32(require('Storage').list(/\.boot\.js/));
-  boot += `if (E.CRC32(require('Storage').read('setting.json'))+E.CRC32(require('Storage').list(/\\.boot\\.js/))!=${CRC})`;
+  var CRC = E.CRC32(require('Storage').read('setting.json'))+E.CRC32(require('Storage').list(/\.boot\.js/))+E.CRC32(process.env.GIT_COMMIT);
+  boot += `if (E.CRC32(require('Storage').read('setting.json'))+E.CRC32(require('Storage').list(/\\.boot\\.js/))+E.CRC32(process.env.GIT_COMMIT)!=${CRC})`;
 }
 boot += ` { eval(require('Storage').read('bootupdate.js')); throw "Storage Updated!"}\n`;
 boot += `E.setFlags({pretokenise:1});\n`;