diff --git a/core/tools/keyctl-proxy b/core/tools/keyctl-proxy
index 9694dc57dd..0495210f5c 100755
--- a/core/tools/keyctl-proxy
+++ b/core/tools/keyctl-proxy
@@ -122,10 +122,10 @@ class KeyctlProxy:
 @click.option(
     "-l", "--listen", "ipaddr", default="0.0.0.0", help="Bind to particular ip address"
 )
-@click.option("-t", "--header-type", "fw_or_type", type=click.Choice(indexmap.keys()))
+@click.option("-t", "--image-type", type=click.Choice(indexmap.keys()))
 @click.option("-d", "--digest")
 @click.argument("fw_file", type=click.File("rb"), required=False)
-def cli(ipaddr, fw_file, fw_or_type, digest):
+def cli(ipaddr, fw_file, image_type, digest):
     """Participate in signing of firmware.
 
     Specify either fw_file to auto-detect type and digest, or use -t and -d to specify
@@ -135,16 +135,16 @@ def cli(ipaddr, fw_file, fw_or_type, digest):
 
     public_keys = None
     if fw_file:
-        if fw_or_type or digest:
+        if image_type or digest:
             raise click.ClickException("Do not specify fw_file together with -t/-d")
 
-        fw_or_type = parse_image(fw_file.read())
-        digest = fw_or_type.digest()
-        public_keys = fw_or_type.public_keys
+        image_type = parse_image(fw_file.read())
+        digest = image_type.digest()
+        public_keys = image_type.public_keys
 
-        click.echo(fw_or_type.format())
+        click.echo(image_type.format())
 
-    if not fw_file and (not fw_or_type or not digest):
+    if not fw_file and (not image_type or not digest):
         raise click.ClickException("Please specify either fw_file or -t and -d")
 
     try:
@@ -153,10 +153,10 @@ def cli(ipaddr, fw_file, fw_or_type, digest):
     except Exception as e:
         raise click.ClickException("Please connect a Trezor and retry.") from e
 
-    pubkey, R = make_commit(fw_or_type, digest, public_keys)
+    pubkey, R = make_commit(image_type, digest, public_keys)
 
     daemon = Pyro4.Daemon(host=ipaddr, port=PORT)
-    proxy = KeyctlProxy(daemon, fw_or_type, digest, (pubkey, R))
+    proxy = KeyctlProxy(daemon, image_type, digest, (pubkey, R))
     uri = daemon.register(proxy, "keyctl")
     click.echo("keyctl-proxy running at URI: {}".format(uri))
     click.echo("Press Ctrl+C to abort.")