diff --git a/liana/src/descriptors/mod.rs b/liana/src/descriptors/mod.rs
index 2456f32e..d5903378 100644
--- a/liana/src/descriptors/mod.rs
+++ b/liana/src/descriptors/mod.rs
@@ -545,20 +545,25 @@ impl LianaDescriptor {
         Ok(self.prune_bip32_derivs(psbt, path_info))
     }
 
+    /// Maximum possible weight in weight units of an unsigned transaction, `tx`,
+    /// after satisfaction, assuming all inputs of `tx` are from this
+    /// descriptor.
+    fn unsigned_tx_max_weight(&self, tx: &bitcoin::Transaction, use_primary_path: bool) -> u64 {
+        let num_inputs: u64 = tx.input.len().try_into().unwrap();
+        let max_sat_weight: u64 = self.max_sat_weight(use_primary_path).try_into().unwrap();
+        // Add weights together before converting to vbytes to avoid rounding up multiple times.
+        tx.weight()
+            .to_wu()
+            .checked_add(max_sat_weight.checked_mul(num_inputs).unwrap())
+            .unwrap()
+    }
+
     /// Maximum possible size in vbytes of an unsigned transaction, `tx`,
     /// after satisfaction, assuming all inputs of `tx` are from this
     /// descriptor.
     pub fn unsigned_tx_max_vbytes(&self, tx: &bitcoin::Transaction, use_primary_path: bool) -> u64 {
         let witness_factor: u64 = WITNESS_SCALE_FACTOR.try_into().unwrap();
-        let num_inputs: u64 = tx.input.len().try_into().unwrap();
-        let max_sat_weight: u64 = self.max_sat_weight(use_primary_path).try_into().unwrap();
-        // Add weights together before converting to vbytes to avoid rounding up multiple times.
-        let tx_wu = tx
-            .weight()
-            .to_wu()
-            .checked_add(max_sat_weight.checked_mul(num_inputs).unwrap())
-            .unwrap();
-        tx_wu
+        self.unsigned_tx_max_weight(tx, use_primary_path)
             .checked_add(witness_factor.checked_sub(1).unwrap())
             .unwrap()
             .checked_div(witness_factor)