diff --git a/tests/upgrade_tests/test_firmware_upgrades.py b/tests/upgrade_tests/test_firmware_upgrades.py
index dfb0695e3c..4cd15430a6 100644
--- a/tests/upgrade_tests/test_firmware_upgrades.py
+++ b/tests/upgrade_tests/test_firmware_upgrades.py
@@ -40,6 +40,7 @@ from . import for_all, for_tags, recovery_old, version_from_tag
 
 if TYPE_CHECKING:
     from trezorlib.debuglink import TrezorClientDebugLink as Client
+    from trezorlib.transport.session import Session
 
 models.T1B1 = dataclasses.replace(models.T1B1, minimum_version=(1, 0, 0))
 models.T2T1 = dataclasses.replace(models.T2T1, minimum_version=(2, 0, 0))
@@ -56,6 +57,32 @@ LABEL = "test"
 STRENGTH = 128
 
 
+def _get_session(client: "Client", passphrase: str | object = "") -> Session:
+    if client.protocol_version != ProtocolVersion.V1:
+        return client.get_session(passphrase=passphrase)
+
+    if client.version >= models.TREZOR_T.minimum_version:
+        return client.get_session(passphrase=passphrase)
+
+    from trezorlib.transport.session import SessionV1
+
+    from ..common import TEST_ADDRESS_N
+
+    session = SessionV1.new(client)
+    resp = session.call_raw(
+        messages.GetAddress(address_n=TEST_ADDRESS_N, coin_name="Testnet")
+    )
+    if isinstance(resp, messages.ButtonRequest):
+        resp = session._callback_button(resp)
+    if isinstance(resp, messages.PassphraseRequest):
+        resp = session.call_raw(messages.PassphraseAck(on_device=True))
+    if isinstance(resp, messages.Deprecated_PassphraseStateRequest):
+        resp = session.call_raw(messages.Deprecated_PassphraseStateAck())
+    if isinstance(resp, messages.ButtonRequest):
+        resp = session._callback_button(resp)
+    return session
+
+
 @for_all()
 def test_upgrade_load(gen: str, tag: str) -> None:
     def asserts(client: "Client"):
@@ -384,11 +411,11 @@ def test_upgrade_shamir_backup(gen: str, tag: Optional[str]):
         assert isinstance(resp, Success)
 
         # Get a passphrase-less and a passphrased address.
-        session = emu.client.get_session()
+        session = _get_session(emu.client)
         address = btc.get_address(session, "Bitcoin", PATH)
         if session.protocol_version == ProtocolVersion.V1:
             session.call(messages.Initialize(new_session=True))
-        new_session = emu.client.get_session(passphrase="TREZOR")
+        new_session = _get_session(emu.client, passphrase="TREZOR")
         address_passphrase = btc.get_address(new_session, "Bitcoin", PATH)
 
         assert emu.client.features.backup_availability == BackupAvailability.Required
@@ -399,8 +426,8 @@ def test_upgrade_shamir_backup(gen: str, tag: Optional[str]):
 
         # Create a backup of the encrypted master secret.
         assert emu.client.features.backup_availability == BackupAvailability.Required
-        session = emu.client.get_session()
-        with session.client as client:
+        session = emu.client.get_seedless_session()
+        with emu.client as client:
             IF = InputFlowSlip39BasicBackup(emu.client, False)
             client.set_input_flow(IF.get())
             device.backup(session)
@@ -424,10 +451,10 @@ def test_upgrade_shamir_backup(gen: str, tag: Optional[str]):
         assert ems.ciphertext == mnemonic_secret
 
         # Check that addresses are the same after firmware upgrade and backup.
-        assert btc.get_address(emu.client.get_session(), "Bitcoin", PATH) == address
+        assert btc.get_address(_get_session(emu.client), "Bitcoin", PATH) == address
         assert (
             btc.get_address(
-                emu.client.get_session(passphrase="TREZOR"), "Bitcoin", PATH
+                _get_session(emu.client, passphrase="TREZOR"), "Bitcoin", PATH
             )
             == address_passphrase
         )