diff --git a/setup/installers.py b/setup/installers.py
index 82731ecee8..90f6fc6c64 100644
--- a/setup/installers.py
+++ b/setup/installers.py
@@ -230,7 +230,10 @@ class ExtDev(Command):
             path = '/cygdrive/c/Program Files/Calibre2/app/bin/{}.pyd'
             bin_dir = '/cygdrive/c/Program Files/Calibre2'
         elif which == 'macos':
-            raise SystemExit("This does not work on macOS because of Apple's stupid code-signing")
+            print(
+                "\n\n\x1b[33;1mWARNING: This does not work on macOS, unless you use un-signed builds with ",
+                ' ./update-on-ox develop\x1b[m',
+                file=sys.stderr, end='\n\n\n')
             host = 'ox'
             path = '/Applications/calibre.app/Contents/Frameworks/plugins/{}.so'
             bin_dir = '/Applications/calibre.app/Contents/MacOS'
diff --git a/update-on-ox b/update-on-ox
index a680f79d3a..9c54ac1937 100755
--- a/update-on-ox
+++ b/update-on-ox
@@ -53,7 +53,11 @@ with open(__file__, 'rb') as f:
 script = script[:script.find('# EOF_REMOTE')].replace('if False:', 'if True:', 1)
 
 with tempfile.NamedTemporaryFile(prefix='install-dmg-', suffix='.py') as f:
-    run('./setup.py osx --dont-shutdown')
+    cmd = './setup.py osx --dont-shutdown'
+    if 'develop' in sys.argv:
+        print('Disabling code-signing and notarization')
+        cmd += ' --dont-sign --dont-notarize'
+    run(cmd)
     f.write(script.encode('utf-8'))
     f.flush()
     run(f'scp dist/{dmg} {f.name} {HOST}:/tmp')