diff --git a/tests/common.py b/tests/common.py
index f1329b0..8d908bf 100644
--- a/tests/common.py
+++ b/tests/common.py
@@ -30,6 +30,9 @@ class TrezorTest(unittest.TestCase):
     def setup_mnemonic_nopin_nopassphrase(self):
         self.client.load_device_by_mnemonic(mnemonic=self.mnemonic12, pin='', passphrase_protection=False, label='test', language='english')
 
+    def setup_mnemonic_pin_nopassphrase(self):
+        self.client.load_device_by_mnemonic(mnemonic=self.mnemonic12, pin=self.pin4, passphrase_protection=False, label='test', language='english')
+
     def setup_mnemonic_pin_passphrase(self):
         self.client.load_device_by_mnemonic(mnemonic=self.mnemonic12, pin=self.pin4, passphrase_protection=True, label='test', language='english')
 
diff --git a/tests/test_msg_applysettings.py b/tests/test_msg_applysettings.py
index 6c0855b..6bb9bc8 100644
--- a/tests/test_msg_applysettings.py
+++ b/tests/test_msg_applysettings.py
@@ -5,6 +5,7 @@ import common
 from trezorlib import messages_pb2 as proto
 
 class TestMsgApplysettings(common.TrezorTest):
+
     def test_apply_settings(self):
         self.setup_mnemonic_pin_passphrase()
         self.assertEqual(self.client.features.label, 'test')
@@ -31,5 +32,37 @@ class TestMsgApplysettings(common.TrezorTest):
 
         self.assertEqual(self.client.features.language, 'english')
 
+    def test_apply_settings_passphrase(self):
+        self.setup_mnemonic_pin_nopassphrase()
+
+        self.assertEqual(self.client.features.passphrase_protection, False)
+
+        with self.client:
+            self.client.set_expected_responses([proto.ButtonRequest(),
+                                                proto.PinMatrixRequest(),
+                                                proto.Success(),
+                                                proto.Features()])
+            self.client.apply_settings(use_passphrase=True)
+
+        self.assertEqual(self.client.features.passphrase_protection, True)
+
+        with self.client:
+            self.client.set_expected_responses([proto.ButtonRequest(),
+                                                proto.PinMatrixRequest(),
+                                                proto.Success(),
+                                                proto.Features()])
+            self.client.apply_settings(use_passphrase=False)
+
+        self.assertEqual(self.client.features.passphrase_protection, False)
+
+        with self.client:
+            self.client.set_expected_responses([proto.ButtonRequest(),
+                                                proto.PinMatrixRequest(),
+                                                proto.Success(),
+                                                proto.Features()])
+            self.client.apply_settings(use_passphrase=True)
+
+        self.assertEqual(self.client.features.passphrase_protection, True)
+
 if __name__ == '__main__':
     unittest.main()
diff --git a/trezorlib/client.py b/trezorlib/client.py
index 37aa264..2d62db6 100644
--- a/trezorlib/client.py
+++ b/trezorlib/client.py
@@ -414,12 +414,14 @@ class ProtocolMixin(object):
 
     @field('message')
     @expect(proto.Success)
-    def apply_settings(self, label=None, language=None):
+    def apply_settings(self, label=None, language=None, use_passphrase=None):
         settings = proto.ApplySettings()
         if label != None:
             settings.label = label
         if language:
             settings.language = language
+        if use_passphrase != None:
+            settings.use_passphrase = use_passphrase
 
         out = self.call(settings)
         self.init_device()  # Reload Features