diff --git a/plugins/trezor.py b/plugins/trezor.py
index 5b305e34..523f8507 100644
--- a/plugins/trezor.py
+++ b/plugins/trezor.py
@@ -83,6 +83,7 @@ class TrezorWallet(NewWallet):
     def __init__(self, storage):
         self.transport = None
         self.client = None
+        self.mpk = None
 
         NewWallet.__init__(self, storage)