diff --git a/CHANGELOG.md b/CHANGELOG.md
index eb1195d9..df61413f 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -8,6 +8,13 @@ A breaking change should be clearly marked in this log.
 ## Unreleased
 
 
+## v0.10.1
+
+### Fixed
+* The `stellar-base` dependency has been upgraded to fix a TypeScript bug ([#665](https://github.com/stellar/js-stellar-base/pull/665)).
+* Decreased bundle size by refactoring `assembleTransaction` to use new abstractions from `stellar-base` ([#120](https://github.com/stellar/js-soroban-client/pull/120)).
+
+
 ## v0.10.0
 
 ### Breaking Changes
diff --git a/package.json b/package.json
index 0ba66d81..206517f7 100644
--- a/package.json
+++ b/package.json
@@ -1,6 +1,6 @@
 {
   "name": "soroban-client",
-  "version": "0.10.0",
+  "version": "0.10.1",
   "description": "A library for working with Stellar's Soroban RPC servers.",
   "author": "Stellar Development Foundation <hello@stellar.org>",
   "homepage": "https://github.com/stellar/js-soroban-client",
@@ -145,7 +145,7 @@
     "eventsource": "^2.0.2",
     "lodash": "^4.17.21",
     "randombytes": "^2.1.0",
-    "stellar-base": "10.0.0-soroban.5",
+    "stellar-base": "10.0.0-soroban.6",
     "toml": "^3.0.0",
     "urijs": "^1.19.1"
   }
diff --git a/src/transaction.ts b/src/transaction.ts
index 48b83ff3..ddce4992 100644
--- a/src/transaction.ts
+++ b/src/transaction.ts
@@ -1,5 +1,4 @@
 import {
-  Account,
   FeeBumpTransaction,
   Operation,
   Transaction,
@@ -9,7 +8,23 @@ import {
 
 import { SorobanRpc } from "./soroban_rpc";
 
-// TODO: Transaction is immutable, so we need to re-build it here. :(
+/**
+ * Combines the given raw transaction alongside the simulation results.
+ *
+ * @param raw   the initial transaction, w/o simulation applied
+ * @param networkPassphrase   the network this simulation applies to
+ * @param simulation  the Soroban RPC simulation result
+ *
+ * @returns a new, cloned transaction with the proper auth and resource (fee,
+ *    footprint) simulation data applied
+ *
+ * @note if the given transaction already has authorization entries in a host
+ *    function invocation (see {@link Operation.invokeHostFunction}), **the
+ *    simulation entries are ignored**.
+ *
+ * @see {Server.simulateTransaction}
+ * @see {Server.prepareTransaction}
+ */
 export function assembleTransaction(
   raw: Transaction | FeeBumpTransaction,
   networkPassphrase: string,
@@ -36,10 +51,10 @@ export function assembleTransaction(
     throw new Error(`simulation results invalid: ${simulation.results}`);
   }
 
-  const source = new Account(raw.source, `${parseInt(raw.sequence, 10) - 1}`);
   const classicFeeNum = parseInt(raw.fee, 10) || 0;
   const minResourceFeeNum = parseInt(simulation.minResourceFee, 10) || 0;
-  const txnBuilder = new TransactionBuilder(source, {
+
+  const txnBuilder = TransactionBuilder.cloneFrom(raw, {
     // automatically update the tx fee that will be set on the resulting tx to
     // the sum of 'classic' fee provided from incoming tx.fee and minResourceFee
     // provided by simulation.
@@ -49,18 +64,16 @@ export function assembleTransaction(
     // in the tx, so can make simplification of total classic fees for the
     // soroban transaction will be equal to incoming tx.fee + minResourceFee.
     fee: (classicFeeNum + minResourceFeeNum).toString(),
-    memo: raw.memo,
-    networkPassphrase,
-    timebounds: raw.timeBounds,
-    ledgerbounds: raw.ledgerBounds,
-    minAccountSequence: raw.minAccountSequence,
-    minAccountSequenceAge: raw.minAccountSequenceAge,
-    minAccountSequenceLedgerGap: raw.minAccountSequenceLedgerGap,
-    extraSigners: raw.extraSigners,
+    // apply the pre-built Soroban Tx Data from simulation onto the Tx
+    sorobanData: simulation.transactionData,
   });
 
   switch (raw.operations[0].type) {
     case "invokeHostFunction":
+      // In this case, we don't want to clone the operation, so we drop it.
+      // @ts-ignore hack because `TransactionBuilder.operations` is private
+      txnBuilder.operations = [];
+
       const invokeOp: Operation.InvokeHostFunction = raw.operations[0];
       const existingAuth = invokeOp.auth ?? [];
       txnBuilder.addOperation(
@@ -81,25 +94,8 @@ export function assembleTransaction(
         })
       );
       break;
-
-    case "bumpFootprintExpiration":
-      txnBuilder.addOperation(
-        Operation.bumpFootprintExpiration(raw.operations[0])
-      );
-      break;
-
-    case "restoreFootprint":
-      txnBuilder.addOperation(Operation.restoreFootprint(raw.operations[0]));
-      break;
   }
 
-  // apply the pre-built Soroban Tx Data from simulation onto the Tx
-  const sorobanTxData = xdr.SorobanTransactionData.fromXDR(
-    simulation.transactionData,
-    "base64"
-  );
-  txnBuilder.setSorobanData(sorobanTxData);
-
   return txnBuilder.build();
 }
 
diff --git a/yarn.lock b/yarn.lock
index 661de2d5..54d46f01 100644
--- a/yarn.lock
+++ b/yarn.lock
@@ -6539,10 +6539,10 @@ statuses@~1.5.0:
   resolved "https://registry.yarnpkg.com/statuses/-/statuses-1.5.0.tgz#161c7dac177659fd9811f43771fa99381478628c"
   integrity sha512-OpZ3zP+jT1PI7I8nemJX4AKmAX070ZkYPVWV/AaKTJl+tXCTGyVdC1a4SL8RUQYEwk/f34ZX8UTykN68FwrqAA==
 
-stellar-base@10.0.0-soroban.5:
-  version "10.0.0-soroban.5"
-  resolved "https://registry.yarnpkg.com/stellar-base/-/stellar-base-10.0.0-soroban.5.tgz#bf12f3a947ac15fa22a61121a705e80ee7eb4834"
-  integrity sha512-4gASMPVftdtuG4JqrRVgjjUyy/gIzv3FTJxR9Y8jfYi7KaduXn5YwaNjRC3UABlScqh2G1ax5+7NFkHhZXg5oA==
+stellar-base@10.0.0-soroban.6:
+  version "10.0.0-soroban.6"
+  resolved "https://registry.yarnpkg.com/stellar-base/-/stellar-base-10.0.0-soroban.6.tgz#b63e3d8e49866a0d1386b2f418c25cb0700f3457"
+  integrity sha512-672OQgps7BjyCvrQywOn7vc/NaaexsH2WrBl+EjlKMDsRp/na0fZcM7+053r9FYzK8nCcXgbOd5IXM6Hmb1pog==
   dependencies:
     base32.js "^0.1.0"
     bignumber.js "^9.1.1"