diff --git a/test/functional/test_framework/txtools.py b/test/functional/test_framework/txtools.py
--- a/test/functional/test_framework/txtools.py
+++ b/test/functional/test_framework/txtools.py
@@ -23,18 +23,17 @@
             tx.vout.append(CTxOut(0, CScript([OP_RETURN])))
         else:
             padding = random.randrange(
-                1 << 8 * padding_len - 1, 1 << 8 * padding_len)
+                1 << 8 * padding_len - 2, 1 << 8 * padding_len - 1)
             tx.vout.append(
                 CTxOut(0, CScript([padding, OP_RETURN])))
         curr_size = len(tx.serialize())
 
     tx.rehash()
 
-# Pad  outputs until it reaches at least min_size
+# Pad outputs until it reaches at least min_size
 
 
 def pad_raw_tx(rawtx_hex, min_size=None):
-
     tx = CTransaction()
     FromHex(tx, rawtx_hex)
     pad_tx(tx, min_size)