diff --git a/test/functional/test_framework/messages.py b/test/functional/test_framework/messages.py
index f6ed8bc83e..e87d5f19e6 100755
--- a/test/functional/test_framework/messages.py
+++ b/test/functional/test_framework/messages.py
@@ -516,6 +516,7 @@ class CTxInWitness(object):
     def is_null(self):
         return len(self.vchIssuanceAmountRangeproof) == 0 \
             and len(self.vchInflationKeysRangeproof) == 0 \
+            and self.peginWitness.is_null() \
             and self.scriptWitness.is_null()