diff --git a/src/commands/mod.rs b/src/commands/mod.rs
index 5d83ba3b..08ee7b90 100644
--- a/src/commands/mod.rs
+++ b/src/commands/mod.rs
@@ -9,8 +9,8 @@ use crate::{
     database::{Coin, DatabaseConnection, DatabaseInterface},
     descriptors,
     spend::{
-        check_output_value, create_spend, unsigned_tx_max_vbytes, AddrInfo, CandidateCoin,
-        CreateSpendRes, SpendCreationError, SpendOutputAddress, TxGetter,
+        check_output_value, create_spend, AddrInfo, CandidateCoin, CreateSpendRes,
+        SpendCreationError, SpendOutputAddress, TxGetter,
     },
     DaemonControl, VERSION,
 };
@@ -29,7 +29,10 @@ use std::{
 };
 
 use miniscript::{
-    bitcoin::{self, address, bip32, psbt::PartiallySignedTransaction as Psbt},
+    bitcoin::{
+        self, address, bip32, constants::WITNESS_SCALE_FACTOR,
+        psbt::PartiallySignedTransaction as Psbt,
+    },
     psbt::PsbtExt,
 };
 use serde::{Deserialize, Serialize};
@@ -176,6 +179,29 @@ impl<'a> TxGetter for BitcoindTxGetter<'a> {
     }
 }
 
+/// An unsigned transaction's maximum possible size in vbytes after satisfaction.
+///
+/// This assumes all inputs are internal (or have the same `max_sat_weight` value).
+///
+/// `tx` is the unsigned transaction.
+///
+/// `max_sat_weight` is the maximum weight difference of an input in the
+/// transaction before and after satisfaction. Must be in weight units.
+fn unsigned_tx_max_vbytes(tx: &bitcoin::Transaction, max_sat_weight: u64) -> u64 {
+    let witness_factor: u64 = WITNESS_SCALE_FACTOR.try_into().unwrap();
+    let num_inputs: u64 = tx.input.len().try_into().unwrap();
+    let tx_wu: u64 = tx
+        .weight()
+        .to_wu()
+        .checked_add(max_sat_weight.checked_mul(num_inputs).unwrap())
+        .unwrap();
+    tx_wu
+        .checked_add(witness_factor.checked_sub(1).unwrap())
+        .unwrap()
+        .checked_div(witness_factor)
+        .unwrap()
+}
+
 impl DaemonControl {
     // Get the derived descriptor for this coin
     fn derived_desc(&self, coin: &Coin) -> descriptors::DerivedSinglePathLianaDesc {
diff --git a/src/spend.rs b/src/spend.rs
index 1b11a339..a57f6f45 100644
--- a/src/spend.rs
+++ b/src/spend.rs
@@ -138,9 +138,9 @@ fn sanity_check_psbt(
     // and increasing the result, which could lead to the feerate in sats/vb falling below 1.
     let tx_wu = tx.weight().to_wu() + (spent_desc.max_sat_weight() * tx.input.len()) as u64;
     let tx_vb = tx_wu
-        .checked_add(descriptors::WITNESS_FACTOR as u64 - 1)
+        .checked_add(WITNESS_SCALE_FACTOR as u64 - 1)
         .unwrap()
-        .checked_div(descriptors::WITNESS_FACTOR as u64)
+        .checked_div(WITNESS_SCALE_FACTOR as u64)
         .unwrap();
     let feerate_sats_vb = abs_fee
         .checked_div(tx_vb)
@@ -361,29 +361,6 @@ fn derived_desc(
     desc.derive(coin.derivation_index, secp)
 }
 
-/// An unsigned transaction's maximum possible size in vbytes after satisfaction.
-///
-/// This assumes all inputs are internal (or have the same `max_sat_weight` value).
-///
-/// `tx` is the unsigned transaction.
-///
-/// `max_sat_weight` is the maximum weight difference of an input in the
-/// transaction before and after satisfaction. Must be in weight units.
-pub fn unsigned_tx_max_vbytes(tx: &bitcoin::Transaction, max_sat_weight: u64) -> u64 {
-    let witness_factor: u64 = WITNESS_SCALE_FACTOR.try_into().unwrap();
-    let num_inputs: u64 = tx.input.len().try_into().unwrap();
-    let tx_wu: u64 = tx
-        .weight()
-        .to_wu()
-        .checked_add(max_sat_weight.checked_mul(num_inputs).unwrap())
-        .unwrap();
-    tx_wu
-        .checked_add(witness_factor.checked_sub(1).unwrap())
-        .unwrap()
-        .checked_div(witness_factor)
-        .unwrap()
-}
-
 #[derive(Debug, Clone, Copy, PartialEq, Eq)]
 pub struct AddrInfo {
     pub index: bip32::ChildNumber,