diff --git a/python/src/trezorlib/client.py b/python/src/trezorlib/client.py
index 1c0bbfa55c..93a97b0f1a 100644
--- a/python/src/trezorlib/client.py
+++ b/python/src/trezorlib/client.py
@@ -257,7 +257,7 @@ class TrezorClient:
     def check_firmware_version(self, warn_only=False):
         if self.is_outdated():
             if warn_only:
-                warnings.warn(OUTDATED_FIRMWARE_ERROR, stacklevel=2)
+                warnings.warn("Firmware is out of date", stacklevel=2)
             else:
                 raise exceptions.OutdatedFirmwareError(OUTDATED_FIRMWARE_ERROR)