diff --git a/modules/abstract-utxo/src/address/fixedScript.ts b/modules/abstract-utxo/src/address/fixedScript.ts
index d5ae2e4f56..0f927ebc23 100644
--- a/modules/abstract-utxo/src/address/fixedScript.ts
+++ b/modules/abstract-utxo/src/address/fixedScript.ts
@@ -14,6 +14,7 @@ import {
 import * as utxolib from '@bitgo/utxo-lib';
 import { bitgo } from '@bitgo/utxo-lib';
 import { bip32 } from '@bitgo/secp256k1';
+import * as wasmUtxo from '@bitgo/wasm-utxo';
 
 type ScriptType2Of3 = bitgo.outputScripts.ScriptType2Of3;
 
@@ -56,6 +57,19 @@ export function generateAddressWithChainAndIndex(
   index: number,
   format: CreateAddressFormat | undefined
 ): string {
+  if (utxolib.isTestnet(network)) {
+    // Convert CreateAddressFormat to AddressFormat for wasm-utxo
+    // 'base58' -> 'default', 'cashaddr' -> 'cashaddr'
+    const wasmFormat = format === 'base58' ? 'default' : format;
+    return wasmUtxo.fixedScriptWallet.address(
+      keychains.map((k) => k.pub) as [string, string, string],
+      chain,
+      index,
+      network,
+      wasmFormat
+    );
+  }
+
   const path = '0/0/' + chain + '/' + index;
   const hdNodes = keychains.map(({ pub }) => bip32.fromBase58(pub));
   const derivedKeys = hdNodes.map((hdNode) => hdNode.derivePath(sanitizeLegacyPath(path)).publicKey);
diff --git a/modules/abstract-utxo/test/unit/address.ts b/modules/abstract-utxo/test/unit/address.ts
index 80d4bb7b06..1fa2964b09 100644
--- a/modules/abstract-utxo/test/unit/address.ts
+++ b/modules/abstract-utxo/test/unit/address.ts
@@ -116,6 +116,38 @@ function run(coin: AbstractUtxoCoin) {
       });
     });
 
+    it('respects format parameter', function () {
+      // Only test coins that actually support multiple address formats (BCH/BCHA)
+      // These are the only coins where the format parameter matters
+      const cashaddrPrefixes: Record<string, string> = {
+        bch: 'bitcoincash:',
+        tbch: 'bchtest:',
+        bcha: 'ecash:',
+        tbcha: 'ectest:',
+      };
+
+      const expectedPrefix = cashaddrPrefixes[coin.getChain()];
+      if (!expectedPrefix) {
+        this.skip();
+      }
+
+      const chain = chainCodes[0];
+      const params = { keychains, chain };
+
+      // Generate with cashaddr format
+      const addressCashaddr = generateAddress(coin.network, { ...params, format: 'cashaddr' });
+      coin.isValidAddress(addressCashaddr).should.eql(true);
+      addressCashaddr.should.startWith(expectedPrefix, `cashaddr should start with ${expectedPrefix}`);
+
+      // Generate with base58 format explicitly
+      const addressBase58 = generateAddress(coin.network, { ...params, format: 'base58' });
+      coin.isValidAddress(addressBase58).should.eql(true);
+      addressBase58.should.not.match(/.*:.*/, 'base58 should not contain colon separator');
+
+      // Verify formats produce different strings
+      addressCashaddr.should.not.equal(addressBase58, 'cashaddr and base58 should produce different address strings');
+    });
+
     utxoCoins.forEach((otherCoin) => {
       it(`has expected address compatability with ${otherCoin.getChain()}`, async function () {
         getParameters().forEach((p) => {
diff --git a/modules/abstract-utxo/test/unit/util/unspents.ts b/modules/abstract-utxo/test/unit/util/unspents.ts
index dbb8cd7a29..24ac209f68 100644
--- a/modules/abstract-utxo/test/unit/util/unspents.ts
+++ b/modules/abstract-utxo/test/unit/util/unspents.ts
@@ -1,5 +1,6 @@
 import * as utxolib from '@bitgo/utxo-lib';
 import { getSeed } from '@bitgo/sdk-test';
+import * as wasmUtxo from '@bitgo/wasm-utxo';
 
 import { getReplayProtectionAddresses } from '../../../src';
 
@@ -31,6 +32,9 @@ export function getWalletAddress(
   chain = defaultChain,
   index = 0
 ): string {
+  if (utxolib.isTestnet(network)) {
+    return wasmUtxo.fixedScriptWallet.address(walletKeys, chain, index, network);
+  }
   return utxolib.address.fromOutputScript(getOutputScript(walletKeys, chain, index).scriptPubKey, network);
 }
 
@@ -49,8 +53,7 @@ export function mockWalletUnspent<TNumber extends number | bigint = number>(
   if (chain === undefined) {
     throw new Error(`unspent chain must be set`);
   }
-  const derived = getOutputScript(walletKeys, chain, index);
-  const deriveAddress = utxolib.address.fromOutputScript(derived.scriptPubKey, network);
+  const deriveAddress = getWalletAddress(network, walletKeys, chain, index);
   if (address) {
     if (address !== deriveAddress) {
       throw new Error(`derivedAddress mismatch: ${address} derived=${deriveAddress}`);