diff --git a/core/src/apps/management/recovery_device/__init__.py b/core/src/apps/management/recovery_device/__init__.py
index 1eef93181..515140b8c 100644
--- a/core/src/apps/management/recovery_device/__init__.py
+++ b/core/src/apps/management/recovery_device/__init__.py
@@ -22,6 +22,12 @@ if False:
     from trezor.messages.RecoveryDevice import RecoveryDevice
 
 
+# List of RecoveryDevice fields that can be set when doing dry-run recovery.
+# All except `dry_run` are allowed for T1 compatibility, but their values are ignored.
+# If set, `enforce_wordlist` must be True, because we do not support non-enforcing.
+DRY_RUN_ALLOWED_FIELDS = ("dry_run", "word_count", "enforce_wordlist", "type")
+
+
 async def recovery_device(ctx: wire.Context, msg: RecoveryDevice) -> Success:
     """
     Recover BIP39/SLIP39 seed into empty device.
@@ -29,7 +35,7 @@ async def recovery_device(ctx: wire.Context, msg: RecoveryDevice) -> Success:
     User starts the process here using the RecoveryDevice msg and then they can unplug
     the device anytime and continue without a computer.
     """
-    _check_state(msg)
+    _validate(msg)
 
     if storage.recovery.is_in_progress():
         return await recovery_process(ctx)
@@ -43,27 +49,26 @@ async def recovery_device(ctx: wire.Context, msg: RecoveryDevice) -> Success:
             await show_pin_invalid(ctx)
             raise wire.PinInvalid("PIN invalid")
 
-    # set up pin if requested
-    if msg.pin_protection:
-        if msg.dry_run:
-            raise wire.ProcessError("Can't setup PIN during dry_run recovery.")
-        newpin = await request_pin_confirm(ctx, allow_cancel=False)
-        config.change_pin(pin_to_int(""), pin_to_int(newpin), None, None)
-
-    if msg.u2f_counter:
-        storage.device.set_u2f_counter(msg.u2f_counter)
-    storage.device.load_settings(
-        label=msg.label, use_passphrase=msg.passphrase_protection
-    )
+    if not msg.dry_run:
+        # set up pin if requested
+        if msg.pin_protection:
+            newpin = await request_pin_confirm(ctx, allow_cancel=False)
+            config.change_pin(pin_to_int(""), pin_to_int(newpin), None, None)
+
+        if msg.u2f_counter is not None:
+            storage.device.set_u2f_counter(msg.u2f_counter)
+        storage.device.load_settings(
+            label=msg.label, use_passphrase=msg.passphrase_protection
+        )
+
     storage.recovery.set_in_progress(True)
-    if msg.dry_run:
-        storage.recovery.set_dry_run(msg.dry_run)
+    storage.recovery.set_dry_run(bool(msg.dry_run))
 
     workflow.replace_default(recovery_homescreen)
     return await recovery_process(ctx)
 
 
-def _check_state(msg: RecoveryDevice) -> None:
+def _validate(msg: RecoveryDevice) -> None:
     if not msg.dry_run and storage.is_initialized():
         raise wire.UnexpectedMessage("Already initialized")
     if msg.dry_run and not storage.is_initialized():
@@ -74,6 +79,14 @@ def _check_state(msg: RecoveryDevice) -> None:
             "Value enforce_wordlist must be True, Trezor Core enforces words automatically."
         )
 
+    if msg.dry_run:
+        # check that only allowed fields are set
+        for key, value in msg.__dict__.items():
+            if key not in DRY_RUN_ALLOWED_FIELDS and value is not None:
+                raise wire.ProcessError(
+                    "Forbidden field set in dry-run: {}".format(key)
+                )
+
 
 async def _continue_dialog(ctx: wire.Context, msg: RecoveryDevice) -> None:
     if not msg.dry_run:
diff --git a/legacy/firmware/fsm_msg_common.h b/legacy/firmware/fsm_msg_common.h
index ebe0116eb..d84b47abb 100644
--- a/legacy/firmware/fsm_msg_common.h
+++ b/legacy/firmware/fsm_msg_common.h
@@ -403,6 +403,12 @@ void fsm_msgRecoveryDevice(const RecoveryDevice *msg) {
   const bool dry_run = msg->has_dry_run ? msg->dry_run : false;
   if (!dry_run) {
     CHECK_NOT_INITIALIZED
+  } else {
+    CHECK_INITIALIZED
+    CHECK_PARAM(!msg->has_passphrase_protection && !msg->has_pin_protection &&
+                    !msg->has_language && !msg->has_label &&
+                    !msg->has_u2f_counter,
+                _("Forbidden field set in dry-run"))
   }
 
   CHECK_PARAM(!msg->has_word_count || msg->word_count == 12 ||
diff --git a/python/src/trezorlib/device.py b/python/src/trezorlib/device.py
index 823d1c94b..51decd4e3 100644
--- a/python/src/trezorlib/device.py
+++ b/python/src/trezorlib/device.py
@@ -18,7 +18,7 @@ import os
 import time
 import warnings
 
-from . import messages as proto
+from . import messages
 from .exceptions import Cancelled
 from .tools import expect, session
 from .transport import enumerate_devices, get_transport
@@ -44,7 +44,7 @@ class TrezorDevice:
         return get_transport(path, prefix_search=False)
 
 
-@expect(proto.Success, field="message")
+@expect(messages.Success, field="message")
 def apply_settings(
     client,
     label=None,
@@ -55,7 +55,7 @@ def apply_settings(
     auto_lock_delay_ms=None,
     display_rotation=None,
 ):
-    settings = proto.ApplySettings()
+    settings = messages.ApplySettings()
     if label is not None:
         settings.label = label
     if language:
@@ -76,30 +76,30 @@ def apply_settings(
     return out
 
 
-@expect(proto.Success, field="message")
+@expect(messages.Success, field="message")
 def apply_flags(client, flags):
-    out = client.call(proto.ApplyFlags(flags=flags))
+    out = client.call(messages.ApplyFlags(flags=flags))
     client.init_device()  # Reload Features
     return out
 
 
-@expect(proto.Success, field="message")
+@expect(messages.Success, field="message")
 def change_pin(client, remove=False):
-    ret = client.call(proto.ChangePin(remove=remove))
+    ret = client.call(messages.ChangePin(remove=remove))
     client.init_device()  # Re-read features
     return ret
 
 
-@expect(proto.Success, field="message")
+@expect(messages.Success, field="message")
 def sd_protect(client, operation):
-    ret = client.call(proto.SdProtect(operation=operation))
+    ret = client.call(messages.SdProtect(operation=operation))
     client.init_device()
     return ret
 
 
-@expect(proto.Success, field="message")
+@expect(messages.Success, field="message")
 def wipe(client):
-    ret = client.call(proto.WipeDevice())
+    ret = client.call(messages.WipeDevice())
     client.init_device()
     return ret
 
@@ -112,7 +112,7 @@ def recover(
     label=None,
     language="english",
     input_callback=None,
-    type=proto.RecoveryDeviceType.ScrambledWords,
+    type=messages.RecoveryDeviceType.ScrambledWords,
     dry_run=False,
     u2f_counter=None,
 ):
@@ -130,32 +130,32 @@ def recover(
     if u2f_counter is None:
         u2f_counter = int(time.time())
 
-    res = client.call(
-        proto.RecoveryDevice(
-            word_count=word_count,
-            passphrase_protection=bool(passphrase_protection),
-            pin_protection=bool(pin_protection),
-            label=label,
-            language=language,
-            enforce_wordlist=True,
-            type=type,
-            dry_run=dry_run,
-            u2f_counter=u2f_counter,
-        )
+    msg = messages.RecoveryDevice(
+        word_count=word_count, enforce_wordlist=True, type=type, dry_run=dry_run
     )
 
-    while isinstance(res, proto.WordRequest):
+    if not dry_run:
+        # set additional parameters
+        msg.passphrase_protection = passphrase_protection
+        msg.pin_protection = pin_protection
+        msg.label = label
+        msg.language = language
+        msg.u2f_counter = u2f_counter
+
+    res = client.call(msg)
+
+    while isinstance(res, messages.WordRequest):
         try:
             inp = input_callback(res.type)
-            res = client.call(proto.WordAck(word=inp))
+            res = client.call(messages.WordAck(word=inp))
         except Cancelled:
-            res = client.call(proto.Cancel())
+            res = client.call(messages.Cancel())
 
     client.init_device()
     return res
 
 
-@expect(proto.Success, field="message")
+@expect(messages.Success, field="message")
 @session
 def reset(
     client,
@@ -168,7 +168,7 @@ def reset(
     u2f_counter=0,
     skip_backup=False,
     no_backup=False,
-    backup_type=proto.BackupType.Bip39,
+    backup_type=messages.BackupType.Bip39,
 ):
     if client.features.initialized:
         raise RuntimeError(
@@ -182,7 +182,7 @@ def reset(
             strength = 128
 
     # Begin with device reset workflow
-    msg = proto.ResetDevice(
+    msg = messages.ResetDevice(
         display_random=bool(display_random),
         strength=strength,
         passphrase_protection=bool(passphrase_protection),
@@ -196,17 +196,17 @@ def reset(
     )
 
     resp = client.call(msg)
-    if not isinstance(resp, proto.EntropyRequest):
+    if not isinstance(resp, messages.EntropyRequest):
         raise RuntimeError("Invalid response, expected EntropyRequest")
 
     external_entropy = os.urandom(32)
     # LOG.debug("Computer generated entropy: " + external_entropy.hex())
-    ret = client.call(proto.EntropyAck(entropy=external_entropy))
+    ret = client.call(messages.EntropyAck(entropy=external_entropy))
     client.init_device()
     return ret
 
 
-@expect(proto.Success, field="message")
+@expect(messages.Success, field="message")
 def backup(client):
-    ret = client.call(proto.BackupDevice())
+    ret = client.call(messages.BackupDevice())
     return ret
diff --git a/tests/device_tests/test_msg_recoverydevice_bip39_dryrun.py b/tests/device_tests/test_msg_recoverydevice_bip39_dryrun.py
index f651ac420..746b469b0 100644
--- a/tests/device_tests/test_msg_recoverydevice_bip39_dryrun.py
+++ b/tests/device_tests/test_msg_recoverydevice_bip39_dryrun.py
@@ -16,54 +16,190 @@
 
 import pytest
 
-from trezorlib import messages as proto
+from trezorlib import device, exceptions, messages, protobuf
 
+from .. import buttons
 from ..common import MNEMONIC12
 
 
+def do_recover_legacy(client, mnemonic, **kwargs):
+    def input_callback(_):
+        word, pos = client.debug.read_recovery_word()
+        if pos != 0:
+            word = mnemonic[pos - 1]
+            mnemonic[pos - 1] = None
+            assert word is not None
+
+        return word
+
+    ret = device.recover(
+        client,
+        dry_run=True,
+        word_count=len(mnemonic),
+        type=messages.RecoveryDeviceType.ScrambledWords,
+        input_callback=input_callback,
+        **kwargs
+    )
+    # if the call succeeded, check that all words have been used
+    assert all(m is None for m in mnemonic)
+    return ret
+
+
+def do_recover_core(client, mnemonic, **kwargs):
+    def input_flow():
+        yield
+        layout = client.debug.wait_layout()
+        assert "check the recovery seed" in layout.text
+        client.debug.click(buttons.OK)
+
+        yield
+        layout = client.debug.wait_layout()
+        assert "Select number of words" in layout.text
+        client.debug.click(buttons.OK)
+
+        yield
+        layout = client.debug.wait_layout()
+        assert layout.text == "WordSelector"
+        # click the number
+        word_option_offset = 6
+        word_options = (12, 18, 20, 24, 33)
+        index = word_option_offset + word_options.index(len(mnemonic))
+        client.debug.click(buttons.grid34(index % 3, index // 3))
+
+        yield
+        layout = client.debug.wait_layout()
+        assert "Enter recovery seed" in layout.text
+        client.debug.click(buttons.OK)
+
+        yield
+        for word in mnemonic:
+            client.debug.input(word)
+
+        yield
+        client.debug.click(buttons.OK)
+
+    with client:
+        client.set_input_flow(input_flow)
+        return device.recover(client, dry_run=True, **kwargs)
+
+
+def do_recover(client, mnemonic):
+    if client.features.model == "1":
+        return do_recover_legacy(client, mnemonic)
+    else:
+        return do_recover_core(client, mnemonic)
+
+
+@pytest.mark.setup_client(mnemonic=MNEMONIC12)
+def test_dry_run(client):
+    ret = do_recover(client, MNEMONIC12.split(" "))
+    assert isinstance(ret, messages.Success)
+
+
+@pytest.mark.setup_client(mnemonic=MNEMONIC12)
+def test_seed_mismatch(client):
+    with pytest.raises(exceptions.TrezorFailure) as exc:
+        do_recover(client, ["all"] * 12)
+    assert "does not match the one in the device" in exc.value.failure.message
+
+
 @pytest.mark.skip_t2
-class TestMsgRecoverydeviceDryrun:
-    def recovery_loop(self, client, mnemonic, result):
-        ret = client.call_raw(
-            proto.RecoveryDevice(
-                word_count=12,
-                passphrase_protection=False,
-                pin_protection=False,
-                label="label",
-                language="english",
-                enforce_wordlist=True,
-                dry_run=True,
-            )
-        )
-
-        fakes = 0
-        for _ in range(int(12 * 2)):
-            assert isinstance(ret, proto.WordRequest)
-            (word, pos) = client.debug.read_recovery_word()
-
-            if pos != 0:
-                ret = client.call_raw(proto.WordAck(word=mnemonic[pos - 1]))
-                mnemonic[pos - 1] = None
-            else:
-                ret = client.call_raw(proto.WordAck(word=word))
-                fakes += 1
-
-            print(mnemonic)
-
-        assert isinstance(ret, proto.ButtonRequest)
-        client.debug.press_yes()
-
-        ret = client.call_raw(proto.ButtonAck())
-        assert isinstance(ret, result)
-
-    def test_correct_notsame(self, client):
-        mnemonic = MNEMONIC12.split(" ")
-        self.recovery_loop(client, mnemonic, proto.Failure)
-
-    def test_correct_same(self, client):
-        mnemonic = ["all"] * 12
-        self.recovery_loop(client, mnemonic, proto.Success)
-
-    def test_incorrect(self, client):
-        mnemonic = ["stick"] * 12
-        self.recovery_loop(client, mnemonic, proto.Failure)
+def test_invalid_seed_t1(client):
+    with pytest.raises(exceptions.TrezorFailure) as exc:
+        do_recover(client, ["stick"] * 12)
+    assert "Invalid seed" in exc.value.failure.message
+
+
+@pytest.mark.skip_t1
+def test_invalid_seed_core(client):
+    def input_flow():
+        yield
+        layout = client.debug.wait_layout()
+        assert "check the recovery seed" in layout.text
+        client.debug.click(buttons.OK)
+
+        yield
+        layout = client.debug.wait_layout()
+        assert "Select number of words" in layout.text
+        client.debug.click(buttons.OK)
+
+        yield
+        layout = client.debug.wait_layout()
+        assert layout.text == "WordSelector"
+        # select 12 words
+        client.debug.click(buttons.grid34(0, 2))
+
+        yield
+        layout = client.debug.wait_layout()
+        assert "Enter recovery seed" in layout.text
+        client.debug.click(buttons.OK)
+
+        yield
+        for _ in range(12):
+            client.debug.input("stick")
+
+        code = yield
+        layout = client.debug.wait_layout()
+        assert code == messages.ButtonRequestType.Warning
+        assert "invalid recovery seed" in layout.text
+        client.debug.click(buttons.OK)
+
+        yield
+        # retry screen
+        layout = client.debug.wait_layout()
+        assert "Select number of words" in layout.text
+        client.debug.click(buttons.CANCEL)
+
+        yield
+        layout = client.debug.wait_layout()
+        assert "abort" in layout.text
+        client.debug.click(buttons.OK)
+
+    with client:
+        client.set_input_flow(input_flow)
+        with pytest.raises(exceptions.Cancelled):
+            return device.recover(client, dry_run=True)
+
+
+@pytest.mark.setup_client(uninitialized=True)
+def test_uninitialized(client):
+    with pytest.raises(exceptions.TrezorFailure) as exc:
+        do_recover(client, ["all"] * 12)
+    assert "not initialized" in exc.value.failure.message
+
+
+DRY_RUN_ALLOWED_FIELDS = ("dry_run", "word_count", "enforce_wordlist", "type")
+
+
+def _make_bad_params():
+    """Generate a list of field names that must NOT be set on a dry-run message,
+    and default values of the appropriate type.
+    """
+    for fname, ftype, _ in messages.RecoveryDevice.get_fields().values():
+        if fname in DRY_RUN_ALLOWED_FIELDS:
+            continue
+
+        if ftype is protobuf.UVarintType:
+            yield fname, 1
+        elif ftype is protobuf.BoolType:
+            yield fname, True
+        elif ftype is protobuf.UnicodeType:
+            yield fname, "test"
+        else:
+            # Someone added a field to RecoveryDevice of a type that has no assigned
+            # default value. This test must be fixed.
+            raise RuntimeError("unknown field in RecoveryDevice")
+
+
+@pytest.mark.parametrize("field_name, field_value", _make_bad_params())
+def test_bad_parameters(client, field_name, field_value):
+    msg = messages.RecoveryDevice(
+        dry_run=True,
+        word_count=12,
+        enforce_wordlist=True,
+        type=messages.RecoveryDeviceType.ScrambledWords,
+    )
+    setattr(msg, field_name, field_value)
+    with pytest.raises(exceptions.TrezorFailure) as exc:
+        client.call(msg)
+    assert "Forbidden field set in dry-run" in exc.value.failure.message