diff --git a/python/src/trezorlib/debuglink.py b/python/src/trezorlib/debuglink.py
index 758b9f782c..5c71aa8dcf 100644
--- a/python/src/trezorlib/debuglink.py
+++ b/python/src/trezorlib/debuglink.py
@@ -160,6 +160,10 @@ class DebugLink:
     def flash_erase(self, sector):
         self._call(proto.DebugLinkFlashErase(sector=sector), nowait=True)
 
+    @expect(proto.Success)
+    def erase_sd_card(self, format=True):
+        return self._call(proto.DebugLinkEraseSdCard(format=format))
+
 
 class NullDebugLink(DebugLink):
     def __init__(self):
diff --git a/tests/conftest.py b/tests/conftest.py
index 2d0d4c2636..42be2759ca 100644
--- a/tests/conftest.py
+++ b/tests/conftest.py
@@ -81,10 +81,8 @@ def client(request):
     if request.node.get_closest_marker("skip_t1") and client.features.model == "1":
         pytest.skip("Test excluded on Trezor 1")
 
-    if (
-        request.node.get_closest_marker("sd_card")
-        and not client.features.sd_card_present
-    ):
+    sd_marker = request.node.get_closest_marker("sd_card")
+    if sd_marker and not client.features.sd_card_present:
         raise RuntimeError(
             "This test requires SD card.\n"
             "To skip all such tests, run:\n"
@@ -101,6 +99,10 @@ def client(request):
         # we need to reseed before the wipe
         client.debug.reseed(0)
 
+    if sd_marker:
+        should_format = sd_marker.kwargs.get("formatted", True)
+        client.debug.erase_sd_card(format=should_format)
+
     wipe_device(client)
 
     setup_params = dict(
diff --git a/tests/device_tests/test_sdcard.py b/tests/device_tests/test_sdcard.py
new file mode 100644
index 0000000000..36bd019be6
--- /dev/null
+++ b/tests/device_tests/test_sdcard.py
@@ -0,0 +1,45 @@
+# This file is part of the Trezor project.
+#
+# Copyright (C) 2012-2019 SatoshiLabs and contributors
+#
+# This library is free software: you can redistribute it and/or modify
+# it under the terms of the GNU Lesser General Public License version 3
+# as published by the Free Software Foundation.
+#
+# This library is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU Lesser General Public License for more details.
+#
+# You should have received a copy of the License along with this library.
+# If not, see <https://www.gnu.org/licenses/lgpl-3.0.html>.
+
+import pytest
+
+from trezorlib import device, messages
+from trezorlib.exceptions import TrezorFailure
+from trezorlib.messages import SdProtectOperationType as Op
+
+pytestmark = pytest.mark.skip_t1
+
+
+@pytest.mark.sd_card(formatted=False)
+def test_sd_format(client):
+    device.sd_protect(client, Op.ENABLE)
+    assert client.features.sd_protection is True
+
+
+@pytest.mark.sd_card(formatted=False)
+def test_sd_no_format(client):
+    def input_flow():
+        yield  # enable SD protection?
+        client.debug.press_yes()
+
+        yield  # format SD card
+        client.debug.press_no()
+
+    with pytest.raises(TrezorFailure) as e, client:
+        client.set_input_flow(input_flow)
+        device.sd_protect(client, Op.ENABLE)
+
+    assert e.value.failure.code == messages.FailureType.ProcessError