diff --git a/tooling/noir_js/src/witness_generation.ts b/tooling/noir_js/src/witness_generation.ts
index d72033b275a..bce95ba0c5c 100644
--- a/tooling/noir_js/src/witness_generation.ts
+++ b/tooling/noir_js/src/witness_generation.ts
@@ -2,6 +2,7 @@ import { abiEncode } from '@noir-lang/noirc_abi';
 import { validateInputs } from './input_validation.js';
 import { base64Decode } from './base64_decode.js';
 import { WitnessMap, executeCircuit } from '@noir-lang/acvm_js';
+import { witnessMapToUint8Array } from './serialize.js';
 
 // Generates the witnesses needed to feed into the chosen proving system
 export async function generateWitness(compiledProgram, inputs): Promise<WitnessMap> {
@@ -12,12 +13,13 @@ export async function generateWitness(compiledProgram, inputs): Promise<WitnessM
   }
   const witnessMap = abiEncode(compiledProgram.abi, inputs, null);
 
-  // Execute the circuit to generate the rest of the witnesses
+  // Execute the circuit to generate the rest of the witnesses and serialize
+  // them into a Uint8Array.
   try {
     const solvedWitness = await executeCircuit(base64Decode(compiledProgram.bytecode), witnessMap, () => {
       throw Error('unexpected oracle during execution');
     });
-    return solvedWitness;
+    return witnessMapToUint8Array(solvedWitness);
   } catch (err) {
     throw new Error(`Circuit execution failed: ${err}`);
   }
diff --git a/tooling/noir_js/test/node/e2e.test.ts b/tooling/noir_js/test/node/e2e.test.ts
index ddd91cca834..18413074871 100644
--- a/tooling/noir_js/test/node/e2e.test.ts
+++ b/tooling/noir_js/test/node/e2e.test.ts
@@ -1,6 +1,6 @@
 import { expect } from 'chai';
 import assert_lt_json from '../noir_compiled_examples/assert_lt/target/assert_lt.json' assert { type: 'json' };
-import { generateWitness, witnessMapToUint8Array } from '../../src/index.js';
+import { generateWitness } from '../../src/index.js';
 import { Backend } from '../backend/barretenberg.js';
 
 it('end-to-end proof creation and verification (outer)', async () => {
@@ -9,14 +9,13 @@ it('end-to-end proof creation and verification (outer)', async () => {
     x: '2',
     y: '3',
   };
-  const solvedWitness = await generateWitness(assert_lt_json, inputs);
+  const serializedWitness = await generateWitness(assert_lt_json, inputs);
 
   // bb.js part
   //
   // Proof creation
   const prover = new Backend(assert_lt_json.bytecode);
   await prover.init();
-  const serializedWitness = witnessMapToUint8Array(solvedWitness);
   const proof = await prover.generateOuterProof(serializedWitness);
 
   // Proof verification
@@ -30,14 +29,13 @@ it('end-to-end proof creation and verification (inner)', async () => {
     x: '2',
     y: '3',
   };
-  const solvedWitness = await generateWitness(assert_lt_json, inputs);
+  const serializedWitness = await generateWitness(assert_lt_json, inputs);
 
   // bb.js part
   //
   // Proof creation
   const prover = new Backend(assert_lt_json.bytecode);
   await prover.init();
-  const serializedWitness = witnessMapToUint8Array(solvedWitness);
   const proof = await prover.generateInnerProof(serializedWitness);
 
   // Proof verification
@@ -63,13 +61,12 @@ it('[BUG] -- bb.js null function or function signature mismatch (different insta
     x: '2',
     y: '3',
   };
-  const solvedWitness = await generateWitness(assert_lt_json, inputs);
+  const serializedWitness = await generateWitness(assert_lt_json, inputs);
 
   // bb.js part
   const prover = new Backend(assert_lt_json.bytecode);
   await prover.init();
 
-  const serializedWitness = witnessMapToUint8Array(solvedWitness);
   const proof = await prover.generateOuterProof(serializedWitness);
 
   try {
@@ -98,7 +95,7 @@ it('[BUG] -- bb.js null function or function signature mismatch (outer-inner) ',
     x: '2',
     y: '3',
   };
-  const solvedWitness = await generateWitness(assert_lt_json, inputs);
+  const serializedWitness = await generateWitness(assert_lt_json, inputs);
 
   // bb.js part
   //
@@ -106,7 +103,6 @@ it('[BUG] -- bb.js null function or function signature mismatch (outer-inner) ',
   //
   const prover = new Backend(assert_lt_json.bytecode);
   await prover.init();
-  const serializedWitness = witnessMapToUint8Array(solvedWitness);
   // Create a proof using both proving systems, the majority of the time
   // one would only use outer proofs.
   const proofOuter = await prover.generateOuterProof(serializedWitness);