diff --git a/sdk/test/utxo.test.ts b/sdk/test/utxo.test.ts
index 801c5f0a..eb3aa18f 100644
--- a/sdk/test/utxo.test.ts
+++ b/sdk/test/utxo.test.ts
@@ -348,8 +348,13 @@ describe('UTXO Tests', () => {
 
         const maxSpendableBalance = cardinalOutputs.reduce((acc, output) => acc + output.value, 0);
 
-        // spend 90% of max spendable amount
-        await createBitcoinPsbt(paymentAddress, paymentAddress, Math.floor(maxSpendableBalance * 0.9), pubkey);
+        (selectUTXO as Mock).mockImplementationOnce(() => ({ tx: {
+            toPSBT() {
+                return Uint8Array.from(Buffer.from('675f66d3ebcb97c383b48f6cbc37c8d32d57a489caa9ecb7e3691bd76731adaa', 'hex'))
+            }
+        }}))
+        
+        await createBitcoinPsbt(paymentAddress, paymentAddress, maxSpendableBalance, pubkey);
 
         const [possibleInputs] = (selectUTXO as Mock).mock.lastCall || [];