diff --git a/tests/test_msg_verifymessage.py b/tests/test_msg_verifymessage.py
index 02e1f17..7760dad 100644
--- a/tests/test_msg_verifymessage.py
+++ b/tests/test_msg_verifymessage.py
@@ -21,7 +21,7 @@ class TestMsgVerifymessage(common.TrezorTest):
         ret = self.client.verify_message('moRDikgmxcpouFtqnKnVVzLYgkDD2gQ3sk', sig, 'Ahoj')
         self.assertTrue(ret)
 
-    def test_message_verify(self):
+    def test_message_verify_address(self):
         self.setup_mnemonic_nopin_nopassphrase()
 
         # uncompressed pubkey - OK
@@ -32,7 +32,7 @@ class TestMsgVerifymessage(common.TrezorTest):
         )
         self.assertTrue(res)
 
-        # uncompressed pubkey - FAIL
+        # uncompressed pubkey - FAIL - wrong sig
         res = self.client.verify_message(
             '1JwSSubhmg6iPtRjtyqhUYYH7bZg3Lfy1T',
             binascii.unhexlify('1ba77e01a9e17ba158b96200000000dfed676ffc2b4bada24e58f784458b52b97421470d001d53d5880cf5e10e76f02be3e80bf21e18398cbd41e8c3b4af74c8c2'),
@@ -40,6 +40,14 @@ class TestMsgVerifymessage(common.TrezorTest):
         )
         self.assertFalse(res)
 
+        # uncompressed pubkey - FAIL - wrong msg
+        res = self.client.verify_message(
+            '1JwSSubhmg6iPtRjtyqhUYYH7bZg3Lfy1T',
+            binascii.unhexlify('1ba77e01a9e17ba158b962cfef5f13dfed676ffc2b4bada24e58f784458b52b97421470d001d53d5880cf5e10e76f02be3e80bf21e18398cbd41e8c3b4af74c8c2'),
+            'This is an example of a signed message!'
+        )
+        self.assertFalse(res)
+
         # compressed pubkey - OK
         res = self.client.verify_message(
             '1C7zdTfnkzmr13HfA2vNm5SJYRK6nEKyq8',
@@ -47,7 +55,7 @@ class TestMsgVerifymessage(common.TrezorTest):
             'This is an example of a signed message.')
         self.assertTrue(res)
 
-        # compressed pubkey - FAIL
+        # compressed pubkey - FAIL - wrong sig
         res = self.client.verify_message(
             '1C7zdTfnkzmr13HfA2vNm5SJYRK6nEKyq8',
             binascii.unhexlify('1f44e3e461f7ca9f57c472000000004df1de1dadefb6551a32d1907b80c74d5a1fbfd6daaba12dd8cb06699ce3f6941fbe0f3957b5802d13076181046e741eaaaf'),
@@ -55,6 +63,13 @@ class TestMsgVerifymessage(common.TrezorTest):
         )
         self.assertFalse(res)
 
+        # compressed pubkey - FAIL - wrong msg
+        res = self.client.verify_message(
+            '1C7zdTfnkzmr13HfA2vNm5SJYRK6nEKyq8',
+            binascii.unhexlify('1f44e3e461f7ca9f57c472ce1a28214df1de1dadefb6551a32d1907b80c74d5a1fbfd6daaba12dd8cb06699ce3f6941fbe0f3957b5802d13076181046e741eaaaf'),
+            'This is an example of a signed message!')
+        self.assertFalse(res)
+
         # trezor pubkey - OK
         res = self.client.verify_message(
             '14LmW5k4ssUrtbAB4255zdqv3b4w1TuX9e',
@@ -63,7 +78,7 @@ class TestMsgVerifymessage(common.TrezorTest):
         )
         self.assertTrue(res)
 
-        # trezor pubkey - FAIL
+        # trezor pubkey - FAIL - wrong sig
         res = self.client.verify_message(
             '14LmW5k4ssUrtbAB4255zdqv3b4w1TuX9e',
             binascii.unhexlify('209e23edf0e4e47ff1de000002cd78c50e74ef018ee8a6adf35ae17c7a9b0dd96f48b493fd7dbab03efb6f439c6383c9523b3bbc5f1a7d158a6af90ab154e9be80'),
@@ -71,6 +86,87 @@ class TestMsgVerifymessage(common.TrezorTest):
         )
         self.assertFalse(res)
 
+        # trezor pubkey - FAIL - wrong msg
+        res = self.client.verify_message(
+            '14LmW5k4ssUrtbAB4255zdqv3b4w1TuX9e',
+            binascii.unhexlify('209e23edf0e4e47ff1dec27f32cd78c50e74ef018ee8a6adf35ae17c7a9b0dd96f48b493fd7dbab03efb6f439c6383c9523b3bbc5f1a7d158a6af90ab154e9be80'),
+            'This is an example of a signed message!'
+        )
+        self.assertFalse(res)
+
+    def test_message_verify_noaddress(self):
+        self.setup_mnemonic_nopin_nopassphrase()
+
+        # uncompressed pubkey - OK
+        res = self.client.verify_message(
+            None,
+            binascii.unhexlify('1ba77e01a9e17ba158b962cfef5f13dfed676ffc2b4bada24e58f784458b52b97421470d001d53d5880cf5e10e76f02be3e80bf21e18398cbd41e8c3b4af74c8c2'),
+            'This is an example of a signed message.'
+        )
+        self.assertTrue(res)
+
+        # uncompressed pubkey - FAIL - wrong sig
+        res = self.client.verify_message(
+            None,
+            binascii.unhexlify('1ba77e01a9e17ba158b96200000000dfed676ffc2b4bada24e58f784458b52b97421470d001d53d5880cf5e10e76f02be3e80bf21e18398cbd41e8c3b4af74c8c2'),
+            'This is an example of a signed message.'
+        )
+        self.assertFalse(res)
+
+        # uncompressed pubkey - FAIL - wrong msg
+        res = self.client.verify_message(
+            None,
+            binascii.unhexlify('1ba77e01a9e17ba158b962cfef5f13dfed676ffc2b4bada24e58f784458b52b97421470d001d53d5880cf5e10e76f02be3e80bf21e18398cbd41e8c3b4af74c8c2'),
+            'This is an example of a signed message!'
+        )
+        self.assertFalse(res)
+
+        # compressed pubkey - OK
+        res = self.client.verify_message(
+            None,
+            binascii.unhexlify('1f44e3e461f7ca9f57c472ce1a28214df1de1dadefb6551a32d1907b80c74d5a1fbfd6daaba12dd8cb06699ce3f6941fbe0f3957b5802d13076181046e741eaaaf'),
+            'This is an example of a signed message.')
+        self.assertTrue(res)
+
+        # compressed pubkey - FAIL - wrong sig
+        res = self.client.verify_message(
+            None,
+            binascii.unhexlify('1f44e3e461f7ca9f57c472000000004df1de1dadefb6551a32d1907b80c74d5a1fbfd6daaba12dd8cb06699ce3f6941fbe0f3957b5802d13076181046e741eaaaf'),
+            'This is an example of a signed message.'
+        )
+        self.assertFalse(res)
+
+        # compressed pubkey - FAIL - wrong msg
+        res = self.client.verify_message(
+            None,
+            binascii.unhexlify('1f44e3e461f7ca9f57c472ce1a28214df1de1dadefb6551a32d1907b80c74d5a1fbfd6daaba12dd8cb06699ce3f6941fbe0f3957b5802d13076181046e741eaaaf'),
+            'This is an example of a signed message!')
+        self.assertFalse(res)
+
+        # trezor pubkey - OK
+        res = self.client.verify_message(
+            None,
+            binascii.unhexlify('209e23edf0e4e47ff1dec27f32cd78c50e74ef018ee8a6adf35ae17c7a9b0dd96f48b493fd7dbab03efb6f439c6383c9523b3bbc5f1a7d158a6af90ab154e9be80'),
+            'This is an example of a signed message.'
+        )
+        self.assertTrue(res)
+
+        # trezor pubkey - FAIL - wrong sig
+        res = self.client.verify_message(
+            None,
+            binascii.unhexlify('209e23edf0e4e47ff1de000002cd78c50e74ef018ee8a6adf35ae17c7a9b0dd96f48b493fd7dbab03efb6f439c6383c9523b3bbc5f1a7d158a6af90ab154e9be80'),
+            'This is an example of a signed message.'
+        )
+        self.assertFalse(res)
+
+        # trezor pubkey - FAIL - wrong msg
+        res = self.client.verify_message(
+            None,
+            binascii.unhexlify('209e23edf0e4e47ff1dec27f32cd78c50e74ef018ee8a6adf35ae17c7a9b0dd96f48b493fd7dbab03efb6f439c6383c9523b3bbc5f1a7d158a6af90ab154e9be80'),
+            'This is an example of a signed message!'
+        )
+        self.assertFalse(res)
+
     """
     def test_verify_bitcoind(self):
         self.setup_mnemonic_nopin_nopassphrase()
diff --git a/trezorlib/client.py b/trezorlib/client.py
index f6e2511..eefbcbd 100644
--- a/trezorlib/client.py
+++ b/trezorlib/client.py
@@ -451,7 +451,10 @@ class ProtocolMixin(object):
             pass # it was not UTF8 string
 
         try:
-            resp = self.call(proto.VerifyMessage(address=address, signature=signature, message=message))
+            if address:
+                resp = self.call(proto.VerifyMessage(address=address, signature=signature, message=message))
+            else:
+                resp = self.call(proto.VerifyMessage(signature=signature, message=message))
         except CallException as e:
             resp = e
         if isinstance(resp, proto.Success):