diff --git a/electrum/interface.py b/electrum/interface.py
index 7c3ae041f..20d12a189 100644
--- a/electrum/interface.py
+++ b/electrum/interface.py
@@ -1020,7 +1020,7 @@ class Interface(Logger):
         assert_dict_contains_field(res, field_name='confirmed')
         assert_dict_contains_field(res, field_name='unconfirmed')
         assert_non_negative_integer(res['confirmed'])
-        assert_non_negative_integer(res['unconfirmed'])
+        assert_integer(res['unconfirmed'])
         return res
 
     async def get_txid_from_txpos(self, tx_height: int, tx_pos: int, merkle: bool):