diff --git a/trezorlib/tests/device_tests/common.py b/trezorlib/tests/device_tests/common.py
index 0d351481a9..18dbb7d3e7 100644
--- a/trezorlib/tests/device_tests/common.py
+++ b/trezorlib/tests/device_tests/common.py
@@ -56,6 +56,9 @@ class TrezorTest:
             label="test",
             language="english",
         )
+        if conftest.TREZOR_VERSION == 1:
+            # remove cached PIN (introduced via load_device)
+            self.client.clear_session()
         if conftest.TREZOR_VERSION > 1 and passphrase:
             device.apply_settings(self.client, passphrase_source=PASSPHRASE_ON_HOST)
 
diff --git a/trezorlib/tests/device_tests/test_msg_changepin.py b/trezorlib/tests/device_tests/test_msg_changepin.py
index d9a27e326a..5590f5e249 100644
--- a/trezorlib/tests/device_tests/test_msg_changepin.py
+++ b/trezorlib/tests/device_tests/test_msg_changepin.py
@@ -56,9 +56,6 @@ class TestMsgChangepin(TrezorTest):
         # Check that there's PIN protection now
         features = self.client.call_raw(proto.Initialize())
         assert features.pin_protection is True
-        ret = self.client.call_raw(proto.Ping(pin_protection=True))
-        assert isinstance(ret, proto.PinMatrixRequest)
-        self.client.call_raw(proto.Cancel())
 
         # Check that the PIN is correct
         assert self.client.debug.read_pin()[0] == self.pin6
@@ -105,9 +102,6 @@ class TestMsgChangepin(TrezorTest):
         # Check that there's still PIN protection now
         features = self.client.call_raw(proto.Initialize())
         assert features.pin_protection is True
-        ret = self.client.call_raw(proto.Ping(pin_protection=True))
-        assert isinstance(ret, proto.PinMatrixRequest)
-        self.client.call_raw(proto.Cancel())
 
         # Check that the PIN is correct
         assert self.client.debug.read_pin()[0] == self.pin6
diff --git a/trezorlib/tests/device_tests/test_msg_recoverydevice.py b/trezorlib/tests/device_tests/test_msg_recoverydevice.py
index e1e7ff5ed9..c52a806248 100644
--- a/trezorlib/tests/device_tests/test_msg_recoverydevice.py
+++ b/trezorlib/tests/device_tests/test_msg_recoverydevice.py
@@ -85,11 +85,6 @@ class TestMsgRecoverydevice(TrezorTest):
         assert isinstance(resp, proto.PassphraseRequest)
         self.client.call_raw(proto.Cancel())
 
-        # Do PIN-protected action, PinRequest should be raised
-        resp = self.client.call_raw(proto.Ping(pin_protection=True))
-        assert isinstance(resp, proto.PinMatrixRequest)
-        self.client.call_raw(proto.Cancel())
-
     def test_nopin_nopassphrase(self):
         mnemonic = self.mnemonic12.split(" ")
         ret = self.client.call_raw(
diff --git a/trezorlib/tests/device_tests/test_msg_resetdevice.py b/trezorlib/tests/device_tests/test_msg_resetdevice.py
index 2174333271..8b57837ac5 100644
--- a/trezorlib/tests/device_tests/test_msg_resetdevice.py
+++ b/trezorlib/tests/device_tests/test_msg_resetdevice.py
@@ -176,11 +176,6 @@ class TestMsgResetDevice(TrezorTest):
         assert isinstance(resp, proto.PassphraseRequest)
         self.client.call_raw(proto.Cancel())
 
-        # Do PIN-protected action, PinRequest should be raised
-        resp = self.client.call_raw(proto.Ping(pin_protection=True))
-        assert isinstance(resp, proto.PinMatrixRequest)
-        self.client.call_raw(proto.Cancel())
-
     def test_failed_pin(self):
         # external_entropy = b'zlutoucky kun upel divoke ody' * 2
         strength = 128