diff --git a/bit/transaction.py b/bit/transaction.py
index cfdc1c2..f6db4b2 100644
--- a/bit/transaction.py
+++ b/bit/transaction.py
@@ -313,6 +313,7 @@ def branch_and_bound(d, selected_coins, effective_value, target, fee, sorted_uns
             # To have a deterministic way of inserting inputs when
             # consolidating, we only shuffle the unspents otherwise.
             shuffle(unspents)
+        estimated_fee = 0
         while unspents:
             selected_coins.append(unspents.pop(0))
             estimated_fee = estimate_tx_fee(