diff --git a/sshagent/__main__.py b/sshagent/__main__.py
index d04975e..213956d 100644
--- a/sshagent/__main__.py
+++ b/sshagent/__main__.py
@@ -88,7 +88,7 @@ def trezor_agent():
             if command:
                 command = ['git'] + command
 
-        identity = client.get_identity(label=label, protocol='ssh')
+        identity = client.get_identity(label=label)
         public_key = client.get_public_key(identity=identity)
 
         use_shell = False
@@ -105,7 +105,7 @@ def trezor_agent():
             return
 
         def signer(label, blob):
-            identity = client.get_identity(label=label, protocol='ssh')
+            identity = client.get_identity(label=label)
             return client.sign_ssh_challenge(identity=identity, blob=blob)
 
         try:
diff --git a/sshagent/tests/test_trezor.py b/sshagent/tests/test_trezor.py
index ecf0323..3479fa9 100644
--- a/sshagent/tests/test_trezor.py
+++ b/sshagent/tests/test_trezor.py
@@ -80,7 +80,7 @@ SIG = (b'\x00R\x19T\xf2\x84$\xef#\x0e\xee\x04X\xc6\xc3\x99T`\xd1\xd8\xf7!'
 
 def test_ssh_agent():
     c = client.Client(factory=FactoryMock)
-    ident = c.get_identity(label='localhost:22', protocol='ssh')
+    ident = c.get_identity(label='localhost:22')
     assert ident.host == 'localhost'
     assert ident.proto == 'ssh'
     assert ident.port == '22'
diff --git a/sshagent/trezor/client.py b/sshagent/trezor/client.py
index 589e6e6..ea60d9a 100644
--- a/sshagent/trezor/client.py
+++ b/sshagent/trezor/client.py
@@ -34,11 +34,9 @@ class Client(object):
         self.client.clear_session()  # forget PIN and shutdown screen
         self.client.close()
 
-    def get_identity(self, label, protocol=None):
+    def get_identity(self, label):
         identity = string_to_identity(label, self.factory.identity_type)
-        if protocol is not None:
-            identity.proto = protocol
-
+        identity.proto = 'ssh'
         return identity
 
     def get_public_key(self, identity):