diff --git a/noir-projects/noir-contracts/contracts/docs_example_contract/src/main.nr b/noir-projects/noir-contracts/contracts/docs_example_contract/src/main.nr
index ae0d5e3d40a..6284c1af9a5 100644
--- a/noir-projects/noir-contracts/contracts/docs_example_contract/src/main.nr
+++ b/noir-projects/noir-contracts/contracts/docs_example_contract/src/main.nr
@@ -115,10 +115,13 @@ contract DocsExample {
         // and returns the response.
         // Used to test that we can retrieve values through calls and 
         // correctly return them in the simulation
-        context.call_private_function_no_args(
+        let mut leader: Leader = context.call_private_function_no_args(
             context.this_address(),
             FunctionSelector::from_signature("get_shared_immutable_constrained_private()")
-        ).unpack_into()
+        ).unpack_into();
+
+        leader.points += 1;
+        leader
     }
 
     #[aztec(public)]
@@ -127,10 +130,13 @@ contract DocsExample {
         // and returns the response.
         // Used to test that we can retrieve values through calls and 
         // correctly return them in the simulation
-        context.call_public_function_no_args(
+        let mut leader: Leader = context.call_public_function_no_args(
             context.this_address(),
             FunctionSelector::from_signature("get_shared_immutable_constrained_public()")
-        ).deserialize_into()
+        ).deserialize_into();
+
+        leader.points += 1;
+        leader
     }
 
     #[aztec(public)]
@@ -138,6 +144,12 @@ contract DocsExample {
         storage.shared_immutable.read_public()
     }
 
+    #[aztec(public)]
+    fn get_shared_immutable_constrained_public_multiple() -> pub [Leader; 5] {
+        let a = storage.shared_immutable.read_public();
+        [a, a, a, a, a]
+    }
+
     #[aztec(private)]
     fn get_shared_immutable_constrained_private() -> pub Leader {
         storage.shared_immutable.read_private()
diff --git a/yarn-project/aztec-node/src/aztec-node/server.ts b/yarn-project/aztec-node/src/aztec-node/server.ts
index 7658dd95029..d0bfaa8ff32 100644
--- a/yarn-project/aztec-node/src/aztec-node/server.ts
+++ b/yarn-project/aztec-node/src/aztec-node/server.ts
@@ -671,7 +671,7 @@ export class AztecNodeService implements AztecNode {
       throw reverted[0].revertReason;
     }
     this.log.info(`Simulated tx ${tx.getTxHash()} succeeds`);
-    return returns;
+    return returns[0];
   }
 
   public setConfig(config: Partial<SequencerConfig>): Promise<void> {
diff --git a/yarn-project/aztec.js/src/contract/contract_function_interaction.ts b/yarn-project/aztec.js/src/contract/contract_function_interaction.ts
index 5f8033124db..f0c2a9e3578 100644
--- a/yarn-project/aztec.js/src/contract/contract_function_interaction.ts
+++ b/yarn-project/aztec.js/src/contract/contract_function_interaction.ts
@@ -1,6 +1,6 @@
 import { type FunctionCall, PackedValues, TxExecutionRequest } from '@aztec/circuit-types';
 import { type AztecAddress, FunctionData, GasSettings, TxContext } from '@aztec/circuits.js';
-import { type FunctionAbi, FunctionType, encodeArguments } from '@aztec/foundation/abi';
+import { type FunctionAbi, FunctionType, decodeReturnValues, encodeArguments } from '@aztec/foundation/abi';
 
 import { type Wallet } from '../account/wallet.js';
 import { BaseContractInteraction, type SendMethodOptions } from './base_contract_interaction.js';
@@ -73,7 +73,6 @@ export class ContractFunctionInteraction extends BaseContractInteraction {
    * 2. It supports `unconstrained`, `private` and `public` functions
    * 3. For `private` execution it:
    * 3.a SKIPS the entrypoint and starts directly at the function
-   * 3.b SKIPS public execution entirely
    * 4. For `public` execution it:
    * 4.a Removes the `txRequest` value after ended simulation
    * 4.b Ignores the `from` in the options
@@ -86,10 +85,6 @@ export class ContractFunctionInteraction extends BaseContractInteraction {
       return this.wallet.viewTx(this.functionDao.name, this.args, this.contractAddress, options.from);
     }
 
-    // TODO: If not unconstrained, we return a size 4 array of fields.
-    // TODO: It should instead return the correctly decoded value
-    // TODO: The return type here needs to be fixed! @LHerskind
-
     if (this.functionDao.functionType == FunctionType.SECRET) {
       const nodeInfo = await this.wallet.getNodeInfo();
       const packedArgs = PackedValues.fromValues(encodeArguments(this.functionDao, this.args));
@@ -103,13 +98,15 @@ export class ContractFunctionInteraction extends BaseContractInteraction {
         authWitnesses: [],
         gasSettings: options.gasSettings ?? GasSettings.simulation(),
       });
-      const simulatedTx = await this.pxe.simulateTx(txRequest, false, options.from ?? this.wallet.getAddress());
-      return simulatedTx.privateReturnValues?.[0];
+      const simulatedTx = await this.pxe.simulateTx(txRequest, true, options.from ?? this.wallet.getAddress());
+      const flattened = simulatedTx.privateReturnValues;
+      return flattened ? decodeReturnValues(this.functionDao, flattened) : [];
     } else {
       const txRequest = await this.create();
       const simulatedTx = await this.pxe.simulateTx(txRequest, true);
       this.txRequest = undefined;
-      return simulatedTx.publicReturnValues?.[0];
+      const flattened = simulatedTx.publicReturnValues;
+      return flattened ? decodeReturnValues(this.functionDao, flattened) : [];
     }
   }
 }
diff --git a/yarn-project/circuit-types/src/interfaces/aztec-node.ts b/yarn-project/circuit-types/src/interfaces/aztec-node.ts
index 918630b042e..03e9ddbff8a 100644
--- a/yarn-project/circuit-types/src/interfaces/aztec-node.ts
+++ b/yarn-project/circuit-types/src/interfaces/aztec-node.ts
@@ -7,7 +7,6 @@ import {
   type PUBLIC_DATA_TREE_HEIGHT,
 } from '@aztec/circuits.js';
 import { type L1ContractAddresses } from '@aztec/ethereum';
-import { type ProcessReturnValues } from '@aztec/foundation/abi';
 import { type AztecAddress } from '@aztec/foundation/aztec-address';
 import { type Fr } from '@aztec/foundation/fields';
 import { type ContractClassPublic, type ContractInstanceWithAddress } from '@aztec/types/contracts';
@@ -22,7 +21,7 @@ import {
 } from '../logs/index.js';
 import { type MerkleTreeId } from '../merkle_tree_id.js';
 import { type SiblingPath } from '../sibling_path/index.js';
-import { type Tx, type TxHash, type TxReceipt } from '../tx/index.js';
+import { type ProcessReturnValues, type Tx, type TxHash, type TxReceipt } from '../tx/index.js';
 import { type TxEffect } from '../tx_effect.js';
 import { type SequencerConfig } from './configs.js';
 import { type L2BlockNumber } from './l2_block_number.js';
@@ -283,7 +282,7 @@ export interface AztecNode {
    * This currently just checks that the transaction execution succeeds.
    * @param tx - The transaction to simulate.
    **/
-  simulatePublicCalls(tx: Tx): Promise<ProcessReturnValues[]>;
+  simulatePublicCalls(tx: Tx): Promise<ProcessReturnValues>;
 
   /**
    * Updates the configuration of this node.
diff --git a/yarn-project/circuit-types/src/mocks.ts b/yarn-project/circuit-types/src/mocks.ts
index f0b3c805ad9..73d0ccf6317 100644
--- a/yarn-project/circuit-types/src/mocks.ts
+++ b/yarn-project/circuit-types/src/mocks.ts
@@ -11,7 +11,7 @@ import {
   getContractClassFromArtifact,
 } from '@aztec/circuits.js';
 import { makePublicCallRequest } from '@aztec/circuits.js/testing';
-import { type ContractArtifact, type DecodedReturn } from '@aztec/foundation/abi';
+import { type ContractArtifact } from '@aztec/foundation/abi';
 import { makeTuple } from '@aztec/foundation/array';
 import { times } from '@aztec/foundation/collection';
 import { randomBytes } from '@aztec/foundation/crypto';
@@ -21,7 +21,7 @@ import { type ContractInstanceWithAddress, SerializableContractInstance } from '
 import { EncryptedL2Log } from './logs/encrypted_l2_log.js';
 import { EncryptedFunctionL2Logs, EncryptedTxL2Logs, Note, UnencryptedTxL2Logs } from './logs/index.js';
 import { ExtendedNote } from './notes/index.js';
-import { SimulatedTx, Tx, TxHash } from './tx/index.js';
+import { type ProcessReturnValues, SimulatedTx, Tx, TxHash } from './tx/index.js';
 
 /**
  * Testing utility to create empty logs composed from a single empty log.
@@ -94,7 +94,7 @@ export const mockTxForRollup = (seed = 1, { hasLogs = false }: { hasLogs?: boole
 
 export const mockSimulatedTx = (seed = 1, hasLogs = true) => {
   const tx = mockTx(seed, { hasLogs });
-  const dec: DecodedReturn = [1n, 2n, 3n, 4n];
+  const dec: ProcessReturnValues = [new Fr(1n), new Fr(2n), new Fr(3n), new Fr(4n)];
   return new SimulatedTx(tx, dec, dec);
 };
 
diff --git a/yarn-project/circuit-types/src/tx/simulated_tx.test.ts b/yarn-project/circuit-types/src/tx/simulated_tx.test.ts
index 29cc0019477..167c91259fa 100644
--- a/yarn-project/circuit-types/src/tx/simulated_tx.test.ts
+++ b/yarn-project/circuit-types/src/tx/simulated_tx.test.ts
@@ -6,4 +6,11 @@ describe('simulated_tx', () => {
     const simulatedTx = mockSimulatedTx();
     expect(SimulatedTx.fromJSON(simulatedTx.toJSON())).toEqual(simulatedTx);
   });
+
+  it('convert undefined effects to and from json', () => {
+    const simulatedTx = mockSimulatedTx();
+    simulatedTx.privateReturnValues = undefined;
+    simulatedTx.publicReturnValues = undefined;
+    expect(SimulatedTx.fromJSON(simulatedTx.toJSON())).toEqual(simulatedTx);
+  });
 });
diff --git a/yarn-project/circuit-types/src/tx/simulated_tx.ts b/yarn-project/circuit-types/src/tx/simulated_tx.ts
index febf33cdfb4..baef7a2d4ea 100644
--- a/yarn-project/circuit-types/src/tx/simulated_tx.ts
+++ b/yarn-project/circuit-types/src/tx/simulated_tx.ts
@@ -1,8 +1,9 @@
-import { AztecAddress } from '@aztec/circuits.js';
-import { type ProcessReturnValues } from '@aztec/foundation/abi';
+import { Fr } from '@aztec/circuits.js';
 
 import { Tx } from './tx.js';
 
+export type ProcessReturnValues = Fr[] | undefined;
+
 export class SimulatedTx {
   constructor(
     public tx: Tx,
@@ -15,17 +16,11 @@ export class SimulatedTx {
    * @returns A plain object with SimulatedTx properties.
    */
   public toJSON() {
-    const returnToJson = (data: ProcessReturnValues): string => {
-      const replacer = (key: string, value: any): any => {
-        if (typeof value === 'bigint') {
-          return value.toString() + 'n'; // Indicate bigint with "n"
-        } else if (value instanceof AztecAddress) {
-          return value.toString();
-        } else {
-          return value;
-        }
-      };
-      return JSON.stringify(data, replacer);
+    const returnToJson = (data: ProcessReturnValues | undefined): string => {
+      if (data === undefined) {
+        return JSON.stringify(data);
+      }
+      return JSON.stringify(data.map(fr => fr.toString()));
     };
 
     return {
@@ -41,22 +36,11 @@ export class SimulatedTx {
    * @returns A Tx class object.
    */
   public static fromJSON(obj: any) {
-    const returnFromJson = (json: string): ProcessReturnValues => {
-      if (json == undefined) {
+    const returnFromJson = (json: string): ProcessReturnValues | undefined => {
+      if (json === undefined) {
         return json;
       }
-      const reviver = (key: string, value: any): any => {
-        if (typeof value === 'string') {
-          if (value.match(/\d+n$/)) {
-            // Detect bigint serialization
-            return BigInt(value.slice(0, -1));
-          } else if (value.match(/^0x[a-fA-F0-9]{64}$/)) {
-            return AztecAddress.fromString(value);
-          }
-        }
-        return value;
-      };
-      return JSON.parse(json, reviver);
+      return JSON.parse(json).map(Fr.fromString);
     };
 
     const tx = Tx.fromJSON(obj.tx);
diff --git a/yarn-project/end-to-end/src/e2e_avm_simulator.test.ts b/yarn-project/end-to-end/src/e2e_avm_simulator.test.ts
index 3de9f8a1b0b..1a941a6f685 100644
--- a/yarn-project/end-to-end/src/e2e_avm_simulator.test.ts
+++ b/yarn-project/end-to-end/src/e2e_avm_simulator.test.ts
@@ -80,15 +80,15 @@ describe('e2e_avm_simulator', () => {
     }, 50_000);
 
     it('Can execute ACVM function among AVM functions', async () => {
-      expect(await avmContract.methods.constant_field_acvm().simulate()).toEqual([123456n]);
+      expect(await avmContract.methods.constant_field_acvm().simulate()).toEqual(123456n);
     });
 
     it('Can call AVM function from ACVM', async () => {
-      expect(await avmContract.methods.call_avm_from_acvm().simulate()).toEqual([123456n]);
+      expect(await avmContract.methods.call_avm_from_acvm().simulate()).toEqual(123456n);
     });
 
     it('Can call ACVM function from AVM', async () => {
-      expect(await avmContract.methods.call_acvm_from_avm().simulate()).toEqual([123456n]);
+      expect(await avmContract.methods.call_acvm_from_avm().simulate()).toEqual(123456n);
     });
 
     it('AVM sees settled nullifiers by ACVM', async () => {
@@ -146,7 +146,7 @@ describe('e2e_avm_simulator', () => {
 
       describe('Storage', () => {
         it('Read immutable (initialized) storage (Field)', async () => {
-          expect(await avmContract.methods.read_storage_immutable().simulate()).toEqual([42n]);
+          expect(await avmContract.methods.read_storage_immutable().simulate()).toEqual(42n);
         });
       });
     });
diff --git a/yarn-project/end-to-end/src/e2e_state_vars.test.ts b/yarn-project/end-to-end/src/e2e_state_vars.test.ts
index 56783ceee2e..f13ee0bd420 100644
--- a/yarn-project/end-to-end/src/e2e_state_vars.test.ts
+++ b/yarn-project/end-to-end/src/e2e_state_vars.test.ts
@@ -38,6 +38,7 @@ describe('e2e_state_vars', () => {
       // checking the return values with:
       // 1. A constrained private function that reads it directly
       // 2. A constrained private function that calls another private function that reads.
+      //    The indirect, adds 1 to the point to ensure that we are returning the correct value.
 
       await contract.methods.initialize_shared_immutable(1).send().wait();
 
@@ -45,12 +46,8 @@ describe('e2e_state_vars', () => {
       const b = await contract.methods.get_shared_immutable_constrained_private_indirect().simulate();
       const c = await contract.methods.get_shared_immutable().simulate();
 
-      expect((a as any)[0]).toEqual((c as any)['account'].toBigInt());
-      expect((a as any)[1]).toEqual((c as any)['points']);
-      expect((b as any)[0]).toEqual((c as any)['account'].toBigInt());
-      expect((b as any)[1]).toEqual((c as any)['points']);
-
-      expect(a).toEqual(b);
+      expect(a).toEqual(c);
+      expect(b).toEqual({ account: c.account, points: c.points + 1n });
       await contract.methods.match_shared_immutable(c.account, c.points).send().wait();
     });
 
@@ -58,20 +55,28 @@ describe('e2e_state_vars', () => {
       // Reads the value using an unconstrained function checking the return values with:
       // 1. A constrained public function that reads it directly
       // 2. A constrained public function that calls another public function that reads.
+      //    The indirect, adds 1 to the point to ensure that we are returning the correct value.
 
       const a = await contract.methods.get_shared_immutable_constrained_public().simulate();
       const b = await contract.methods.get_shared_immutable_constrained_public_indirect().simulate();
       const c = await contract.methods.get_shared_immutable().simulate();
 
-      expect((a as any)[0]).toEqual((c as any)['account'].toBigInt());
-      expect((a as any)[1]).toEqual((c as any)['points']);
-      expect((b as any)[0]).toEqual((c as any)['account'].toBigInt());
-      expect((b as any)[1]).toEqual((c as any)['points']);
+      expect(a).toEqual(c);
+      expect(b).toEqual({ account: c.account, points: c.points + 1n });
 
-      expect(a).toEqual(b);
       await contract.methods.match_shared_immutable(c.account, c.points).send().wait();
     });
 
+    it('public multiread of SharedImmutable', async () => {
+      // Reads the value using an unconstrained function checking the return values with:
+      // 1. A constrained public function that reads 5 times directly (going beyond the previous 4 Field return value)
+
+      const a = await contract.methods.get_shared_immutable_constrained_public_multiple().simulate();
+      const c = await contract.methods.get_shared_immutable().simulate();
+
+      expect(a).toEqual([c, c, c, c, c]);
+    });
+
     it('initializing SharedImmutable the second time should fail', async () => {
       // Jest executes the tests sequentially and the first call to initialize_shared_immutable was executed
       // in the previous test, so the call bellow should fail.
diff --git a/yarn-project/foundation/src/abi/decoder.ts b/yarn-project/foundation/src/abi/decoder.ts
index deafe602ae1..c98bac63823 100644
--- a/yarn-project/foundation/src/abi/decoder.ts
+++ b/yarn-project/foundation/src/abi/decoder.ts
@@ -1,20 +1,19 @@
 import { AztecAddress } from '../aztec-address/index.js';
 import { type Fr } from '../fields/index.js';
-import { type ABIParameter, type ABIVariable, type AbiType, type FunctionArtifact } from './abi.js';
+import { type ABIParameter, type ABIVariable, type AbiType, type FunctionAbi } from './abi.js';
 import { isAztecAddressStruct } from './utils.js';
 
 /**
  * The type of our decoded ABI.
  */
 export type DecodedReturn = bigint | boolean | AztecAddress | DecodedReturn[] | { [key: string]: DecodedReturn };
-export type ProcessReturnValues = (DecodedReturn | undefined)[] | undefined;
 
 /**
  * Decodes return values from a function call.
  * Missing support for integer and string.
  */
 class ReturnValuesDecoder {
-  constructor(private artifact: FunctionArtifact, private flattened: Fr[]) {}
+  constructor(private artifact: FunctionAbi, private flattened: Fr[]) {}
 
   /**
    * Decodes a single return value from field to the given type.
@@ -97,7 +96,7 @@ class ReturnValuesDecoder {
  * @param returnValues - The decoded return values.
  * @returns
  */
-export function decodeReturnValues(abi: FunctionArtifact, returnValues: Fr[]) {
+export function decodeReturnValues(abi: FunctionAbi, returnValues: Fr[]) {
   return new ReturnValuesDecoder(abi, returnValues.slice()).decode();
 }
 
diff --git a/yarn-project/pxe/src/pxe_service/pxe_service.ts b/yarn-project/pxe/src/pxe_service/pxe_service.ts
index 45f0a9eb16e..7aa8f8fb00c 100644
--- a/yarn-project/pxe/src/pxe_service/pxe_service.ts
+++ b/yarn-project/pxe/src/pxe_service/pxe_service.ts
@@ -417,8 +417,7 @@ export class PXEService implements PXE {
       }
 
       if (simulatePublic) {
-        // Only one transaction, so we can take index 0.
-        simulatedTx.publicReturnValues = (await this.#simulatePublicCalls(simulatedTx.tx))[0];
+        simulatedTx.publicReturnValues = await this.#simulatePublicCalls(simulatedTx.tx);
       }
 
       if (!msgSender) {
@@ -646,7 +645,7 @@ export class PXEService implements PXE {
     await this.patchPublicCallStackOrdering(publicInputs, enqueuedPublicFunctions);
 
     const tx = new Tx(publicInputs, proof, encryptedLogs, unencryptedLogs, enqueuedPublicFunctions);
-    return new SimulatedTx(tx, [executionResult.returnValues]);
+    return new SimulatedTx(tx, executionResult.returnValues);
   }
 
   /**
diff --git a/yarn-project/simulator/src/client/execution_result.ts b/yarn-project/simulator/src/client/execution_result.ts
index 5118b28d607..9dfe877ba92 100644
--- a/yarn-project/simulator/src/client/execution_result.ts
+++ b/yarn-project/simulator/src/client/execution_result.ts
@@ -4,7 +4,6 @@ import {
   type PrivateCallStackItem,
   type PublicCallRequest,
 } from '@aztec/circuits.js';
-import { type DecodedReturn } from '@aztec/foundation/abi';
 import { type Fr } from '@aztec/foundation/fields';
 
 import { type ACVMField } from '../acvm/index.js';
@@ -40,8 +39,8 @@ export interface ExecutionResult {
   // Needed when we enable chained txs. The new notes can be cached and used in a later transaction.
   /** The notes created in the executed function. */
   newNotes: NoteAndSlot[];
-  /** The decoded return values of the executed function. */
-  returnValues: DecodedReturn;
+  /** The raw return values of the executed function. */
+  returnValues: Fr[];
   /** The nested executions. */
   nestedExecutions: this[];
   /** Enqueued public function execution requests to be picked up by the sequencer. */
diff --git a/yarn-project/simulator/src/client/private_execution.test.ts b/yarn-project/simulator/src/client/private_execution.test.ts
index b3bdc01968b..716232104a6 100644
--- a/yarn-project/simulator/src/client/private_execution.test.ts
+++ b/yarn-project/simulator/src/client/private_execution.test.ts
@@ -433,7 +433,7 @@ describe('Private Execution test suite', () => {
       const artifact = getFunctionArtifact(ChildContractArtifact, 'value');
       const result = await runSimulator({ args: [initialValue], artifact });
 
-      expect(result.returnValues).toEqual([initialValue + privateIncrement]);
+      expect(result.returnValues).toEqual([new Fr(initialValue + privateIncrement)]);
     });
 
     it('parent should call child', async () => {
@@ -452,12 +452,12 @@ describe('Private Execution test suite', () => {
       const args = [childAddress, childSelector];
       const result = await runSimulator({ args, artifact: parentArtifact });
 
-      expect(result.returnValues).toEqual([privateIncrement]);
+      expect(result.returnValues).toEqual([new Fr(privateIncrement)]);
 
       expect(oracle.getFunctionArtifact.mock.calls[0]).toEqual([childAddress, childSelector]);
       expect(oracle.getPortalContractAddress.mock.calls[0]).toEqual([childAddress]);
       expect(result.nestedExecutions).toHaveLength(1);
-      expect(result.nestedExecutions[0].returnValues).toEqual([privateIncrement]);
+      expect(result.nestedExecutions[0].returnValues).toEqual([new Fr(privateIncrement)]);
 
       // check that Aztec.nr calculated the call stack item hash like cpp does
       const expectedCallStackItemHash = result.nestedExecutions[0].callStackItem.hash();
@@ -486,7 +486,7 @@ describe('Private Execution test suite', () => {
       logger.info(`Calling testCodeGen function`);
       const result = await runSimulator({ args, artifact: testCodeGenArtifact });
 
-      expect(result.returnValues).toEqual([argsHash.toBigInt()]);
+      expect(result.returnValues).toEqual([argsHash]);
     });
 
     it('test function should be callable through autogenerated interface', async () => {
@@ -504,11 +504,11 @@ describe('Private Execution test suite', () => {
       const args = [testAddress];
       const result = await runSimulator({ args, artifact: parentArtifact });
 
-      expect(result.returnValues).toEqual([argsHash.toBigInt()]);
+      expect(result.returnValues).toEqual([argsHash]);
       expect(oracle.getFunctionArtifact.mock.calls[0]).toEqual([testAddress, testCodeGenSelector]);
       expect(oracle.getPortalContractAddress.mock.calls[0]).toEqual([testAddress]);
       expect(result.nestedExecutions).toHaveLength(1);
-      expect(result.nestedExecutions[0].returnValues).toEqual([argsHash.toBigInt()]);
+      expect(result.nestedExecutions[0].returnValues).toEqual([argsHash]);
     });
   });
 
@@ -899,7 +899,7 @@ describe('Private Execution test suite', () => {
       const readRequest = sideEffectArrayToValueArray(result.callStackItem.publicInputs.noteHashReadRequests)[0];
       expect(readRequest).toEqual(innerNoteHash);
 
-      expect(result.returnValues).toEqual([amountToTransfer]);
+      expect(result.returnValues).toEqual([new Fr(amountToTransfer)]);
 
       const nullifier = result.callStackItem.publicInputs.newNullifiers[0];
       const siloedNullifierSecretKey = computeSiloedNullifierSecretKey(
@@ -974,7 +974,7 @@ describe('Private Execution test suite', () => {
       const readRequest = execGetThenNullify.callStackItem.publicInputs.noteHashReadRequests[0];
       expect(readRequest.value).toEqual(innerNoteHash);
 
-      expect(execGetThenNullify.returnValues).toEqual([amountToTransfer]);
+      expect(execGetThenNullify.returnValues).toEqual([new Fr(amountToTransfer)]);
 
       const nullifier = execGetThenNullify.callStackItem.publicInputs.newNullifiers[0];
       const siloedNullifierSecretKey = computeSiloedNullifierSecretKey(
@@ -1013,7 +1013,6 @@ describe('Private Execution test suite', () => {
     it('gets the public key for an address', async () => {
       // Tweak the contract artifact so we can extract return values
       const artifact = getFunctionArtifact(TestContractArtifact, 'get_public_key');
-      artifact.returnTypes = [{ kind: 'array', length: 2, type: { kind: 'field' } }];
 
       // Generate a partial address, pubkey, and resulting address
       const completeAddress = CompleteAddress.random();
@@ -1022,7 +1021,7 @@ describe('Private Execution test suite', () => {
 
       oracle.getCompleteAddress.mockResolvedValue(completeAddress);
       const result = await runSimulator({ artifact, args });
-      expect(result.returnValues).toEqual([pubKey.x.toBigInt(), pubKey.y.toBigInt()]);
+      expect(result.returnValues).toEqual([pubKey.x, pubKey.y]);
     });
   });
 
@@ -1046,14 +1045,13 @@ describe('Private Execution test suite', () => {
 
       // Tweak the contract artifact so we can extract return values
       const artifact = getFunctionArtifact(TestContractArtifact, 'get_portal_contract_address');
-      artifact.returnTypes = [{ kind: 'field' }];
 
       const args = [aztecAddressToQuery.toField()];
 
       // Overwrite the oracle return value
       oracle.getPortalContractAddress.mockResolvedValue(portalContractAddress);
       const result = await runSimulator({ artifact, args });
-      expect(result.returnValues).toEqual([portalContractAddress.toField().value]);
+      expect(result.returnValues).toEqual([portalContractAddress.toField()]);
     });
 
     it('this_address should return the current context address', async () => {
@@ -1061,11 +1059,10 @@ describe('Private Execution test suite', () => {
 
       // Tweak the contract artifact so we can extract return values
       const artifact = getFunctionArtifact(TestContractArtifact, 'get_this_address');
-      artifact.returnTypes = [{ kind: 'field' }];
 
       // Overwrite the oracle return value
       const result = await runSimulator({ artifact, args: [], contractAddress });
-      expect(result.returnValues).toEqual([contractAddress.toField().toBigInt()]);
+      expect(result.returnValues).toEqual([contractAddress.toField()]);
     });
 
     it("this_portal_address should return the current context's portal address", async () => {
@@ -1073,11 +1070,10 @@ describe('Private Execution test suite', () => {
 
       // Tweak the contract artifact so we can extract return values
       const artifact = getFunctionArtifact(TestContractArtifact, 'get_this_portal_address');
-      artifact.returnTypes = [{ kind: 'field' }];
 
       // Overwrite the oracle return value
       const result = await runSimulator({ artifact, args: [], portalContractAddress });
-      expect(result.returnValues).toEqual([portalContractAddress.toField().toBigInt()]);
+      expect(result.returnValues).toEqual([portalContractAddress.toField()]);
     });
   });
 
diff --git a/yarn-project/simulator/src/client/private_execution.ts b/yarn-project/simulator/src/client/private_execution.ts
index 7a7b0d13288..d058985d750 100644
--- a/yarn-project/simulator/src/client/private_execution.ts
+++ b/yarn-project/simulator/src/client/private_execution.ts
@@ -1,5 +1,5 @@
 import { type FunctionData, PrivateCallStackItem, PrivateCircuitPublicInputs } from '@aztec/circuits.js';
-import { type AbiType, type FunctionArtifactWithDebugMetadata, decodeReturnValues } from '@aztec/foundation/abi';
+import { type FunctionArtifactWithDebugMetadata } from '@aztec/foundation/abi';
 import { type AztecAddress } from '@aztec/foundation/aztec-address';
 import { Fr } from '@aztec/foundation/fields';
 import { createDebugLogger } from '@aztec/foundation/log';
@@ -53,12 +53,7 @@ export async function executePrivateFunction(
 
   const callStackItem = new PrivateCallStackItem(contractAddress, functionData, publicInputs);
 
-  // Mocking the return type to be an array of 4 fields
-  // TODO: @LHerskind must be updated as we are progressing with the macros to get the information
   const rawReturnValues = await context.unpackReturns(publicInputs.returnsHash);
-  const returnTypes: AbiType[] = [{ kind: 'array', length: rawReturnValues.length, type: { kind: 'field' } }];
-  const mockArtifact = { ...artifact, returnTypes };
-  const returnValues = decodeReturnValues(mockArtifact, rawReturnValues);
 
   const noteHashReadRequestPartialWitnesses = context.getNoteHashReadRequestPartialWitnesses(
     publicInputs.noteHashReadRequests,
@@ -73,7 +68,7 @@ export async function executePrivateFunction(
     acir,
     partialWitness,
     callStackItem,
-    returnValues,
+    returnValues: rawReturnValues,
     noteHashReadRequestPartialWitnesses,
     newNotes,
     vk: Buffer.from(artifact.verificationKey!, 'hex'),
diff --git a/yarn-project/simulator/src/public/abstract_phase_manager.ts b/yarn-project/simulator/src/public/abstract_phase_manager.ts
index cb56906ea2a..c39d240ded7 100644
--- a/yarn-project/simulator/src/public/abstract_phase_manager.ts
+++ b/yarn-project/simulator/src/public/abstract_phase_manager.ts
@@ -1,5 +1,6 @@
 import {
   MerkleTreeId,
+  type ProcessReturnValues,
   type PublicKernelRequest,
   type SimulationError,
   type Tx,
@@ -47,13 +48,6 @@ import {
   makeEmptyProof,
 } from '@aztec/circuits.js';
 import { computeVarArgsHash } from '@aztec/circuits.js/hash';
-import {
-  type AbiType,
-  type DecodedReturn,
-  type FunctionArtifact,
-  type ProcessReturnValues,
-  decodeReturnValues,
-} from '@aztec/foundation/abi';
 import { arrayNonEmptyLength, padArrayEnd } from '@aztec/foundation/collection';
 import { type DebugLogger, createDebugLogger } from '@aztec/foundation/log';
 import { type Tuple } from '@aztec/foundation/serialize';
@@ -236,13 +230,11 @@ export abstract class AbstractPhaseManager {
     // separate public callstacks to be proven by separate public kernel sequences
     // and submitted separately to the base rollup?
 
-    const returns = [];
+    let returns: ProcessReturnValues = undefined;
 
     for (const enqueuedCall of enqueuedCalls) {
       const executionStack: (PublicExecution | PublicExecutionResult)[] = [enqueuedCall];
 
-      let currentReturn: DecodedReturn | undefined = undefined;
-
       // Keep track of which result is for the top/enqueued call
       let enqueuedExecutionResult: PublicExecutionResult | undefined;
 
@@ -301,21 +293,12 @@ export abstract class AbstractPhaseManager {
 
         if (!enqueuedExecutionResult) {
           enqueuedExecutionResult = result;
-
-          // TODO(#5450) Need to use the proper return values here
-          const returnTypes: AbiType[] = [
-            { kind: 'array', length: result.returnValues.length, type: { kind: 'field' } },
-          ];
-          const mockArtifact = { returnTypes } as any as FunctionArtifact;
-
-          currentReturn = decodeReturnValues(mockArtifact, result.returnValues);
+          returns = result.returnValues;
         }
       }
       // HACK(#1622): Manually patches the ordering of public state actions
       // TODO(#757): Enforce proper ordering of public state actions
       patchPublicStorageActionOrdering(kernelOutput, enqueuedExecutionResult!, this.phase);
-
-      returns.push(currentReturn);
     }
 
     // TODO(#3675): This should be done in a public kernel circuit
diff --git a/yarn-project/simulator/src/public/avm_executor.test.ts b/yarn-project/simulator/src/public/avm_executor.test.ts
index d0c0fc234dc..43c1dc7663c 100644
--- a/yarn-project/simulator/src/public/avm_executor.test.ts
+++ b/yarn-project/simulator/src/public/avm_executor.test.ts
@@ -72,6 +72,6 @@ describe('AVM WitGen and Proof Generation', () => {
       const valid = await executor.verifyAvmProof(vk, proof);
       expect(valid).toBe(true);
     },
-    60 * 1000,
-  ); // 60 seconds should be enough to generate the proof with 16-bit range checks
+    120 * 1000,
+  ); // 120 seconds should be enough to generate the proof with 16-bit range checks
 });
diff --git a/yarn-project/simulator/src/public/public_processor.ts b/yarn-project/simulator/src/public/public_processor.ts
index 9354bd6d6e9..b749c2276fa 100644
--- a/yarn-project/simulator/src/public/public_processor.ts
+++ b/yarn-project/simulator/src/public/public_processor.ts
@@ -1,6 +1,7 @@
 import {
   type BlockProver,
   type FailedTx,
+  type ProcessReturnValues,
   type ProcessedTx,
   type PublicKernelRequest,
   type SimulationError,
@@ -13,7 +14,6 @@ import {
 } from '@aztec/circuit-types';
 import { type TxSequencerProcessingStats } from '@aztec/circuit-types/stats';
 import { type GlobalVariables, type Header, type KernelCircuitPublicInputs } from '@aztec/circuits.js';
-import { type ProcessReturnValues } from '@aztec/foundation/abi';
 import { createDebugLogger } from '@aztec/foundation/log';
 import { Timer } from '@aztec/foundation/timer';
 import { PublicExecutor, type PublicStateDB, type SimulationProvider } from '@aztec/simulator';
diff --git a/yarn-project/types/src/abi/contract_artifact.ts b/yarn-project/types/src/abi/contract_artifact.ts
index b1b5ca3d8ac..f2c605a0886 100644
--- a/yarn-project/types/src/abi/contract_artifact.ts
+++ b/yarn-project/types/src/abi/contract_artifact.ts
@@ -117,9 +117,10 @@ type NoirCompiledContractFunction = NoirCompiledContract['functions'][number];
 /**
  * Generates a function build artifact. Replaces verification key with a mock value.
  * @param fn - Noir function entry.
+ * @param contract - Parent contract.
  * @returns Function artifact.
  */
-function generateFunctionArtifact(fn: NoirCompiledContractFunction): FunctionArtifact {
+function generateFunctionArtifact(fn: NoirCompiledContractFunction, contract: NoirCompiledContract): FunctionArtifact {
   if (fn.custom_attributes === undefined) {
     throw new Error(
       `No custom attributes found for contract function ${fn.name}. Try rebuilding the contract with the latest nargo version.`,
@@ -134,10 +135,25 @@ function generateFunctionArtifact(fn: NoirCompiledContractFunction): FunctionArt
     parameters = parameters.slice(1);
   }
 
-  // If the function is secret, the return is the public inputs, which should be omitted
   let returnTypes: AbiType[] = [];
-  if (functionType !== 'secret' && fn.abi.return_type) {
+  if (functionType === FunctionType.UNCONSTRAINED && fn.abi.return_type) {
     returnTypes = [fn.abi.return_type.abi_type];
+  } else {
+    const pathToFind = `${contract.name}::${fn.name}_abi`;
+    const abiStructs: AbiType[] = contract.outputs.structs['functions'];
+
+    const returnStruct = abiStructs.find(a => a.kind === 'struct' && a.path === pathToFind);
+
+    if (returnStruct) {
+      if (returnStruct.kind !== 'struct') {
+        throw new Error('Could not generate contract function artifact');
+      }
+
+      const returnTypeField = returnStruct.fields.find(field => field.name === 'return_type');
+      if (returnTypeField) {
+        returnTypes = [returnTypeField.type];
+      }
+    }
   }
 
   return {
@@ -190,7 +206,7 @@ function hasKernelFunctionInputs(params: ABIParameter[]): boolean {
 function generateContractArtifact(contract: NoirCompiledContract, aztecNrVersion?: string): ContractArtifact {
   return {
     name: contract.name,
-    functions: contract.functions.map(generateFunctionArtifact),
+    functions: contract.functions.map(f => generateFunctionArtifact(f, contract)),
     outputs: contract.outputs,
     fileMap: contract.file_map,
     aztecNrVersion,