diff --git a/packages/arb-avm-cpp/cmachine/arbcore.go b/packages/arb-avm-cpp/cmachine/arbcore.go
index b62b30b8c6..8e423aceea 100644
--- a/packages/arb-avm-cpp/cmachine/arbcore.go
+++ b/packages/arb-avm-cpp/cmachine/arbcore.go
@@ -105,9 +105,9 @@ func (ac *ArbCore) DeliverMessages(previousMessageCount *big.Int, previousSeqBat
 	previousMessageCountPtr := unsafeDataPointer(math.U256Bytes(previousMessageCount))
 	previousSeqBatchAccPtr := unsafeDataPointer(previousSeqBatchAcc.Bytes())
 	seqBatchItemsSlice := sequencerBatchItemsToByteSliceArray(seqBatchItems)
-	defer C.free(seqBatchItemsSlice.slices)
+	defer freeByteSliceArray(seqBatchItemsSlice)
 	delayedMessagesSlice := delayedMessagesToByteSliceArray(delayedMessages)
-	defer C.free(delayedMessagesSlice.slices)
+	defer freeByteSliceArray(delayedMessagesSlice)
 
 	var cReorgSeqBatchItemCount unsafe.Pointer
 	if reorgSeqBatchItemCount != nil {
diff --git a/packages/arb-avm-cpp/cmachine/machine.go b/packages/arb-avm-cpp/cmachine/machine.go
index d5d26acf40..d0a9aeae8f 100644
--- a/packages/arb-avm-cpp/cmachine/machine.go
+++ b/packages/arb-avm-cpp/cmachine/machine.go
@@ -171,17 +171,6 @@ func (m *Machine) ExecuteAssertion(
 	)
 }
 
-// Note: the slices field of the returned struct needs manually freed by C.free
-func bytesArrayToByteSliceArray(bytes [][]byte) C.struct_ByteSliceArrayStruct {
-	byteSlices := encodeByteSliceList(bytes)
-	sliceArrayData := C.malloc(C.size_t(C.sizeof_struct_ByteSliceStruct * len(byteSlices)))
-	sliceArray := (*[1 << 30]C.struct_ByteSliceStruct)(sliceArrayData)[:len(byteSlices):len(byteSlices)]
-	for i, data := range byteSlices {
-		sliceArray[i] = data
-	}
-	return C.struct_ByteSliceArrayStruct{slices: sliceArrayData, count: C.int(len(byteSlices))}
-}
-
 func (m *Machine) ExecuteAssertionAdvanced(
 	maxGas uint64,
 	goOverGas bool,
@@ -196,11 +185,11 @@ func (m *Machine) ExecuteAssertionAdvanced(
 	C.machineExecutionConfigSetMaxGas(conf, C.uint64_t(maxGas), boolToCInt(goOverGas))
 
 	msgData := bytesArrayToByteSliceArray(encodeMachineInboxMessages(messages))
-	defer C.free(msgData.slices)
+	defer freeByteSliceArray(msgData)
 	C.machineExecutionConfigSetInboxMessages(conf, msgData)
 
 	sideloadsData := bytesArrayToByteSliceArray(encodeInboxMessages(sideloads))
-	defer C.free(sideloadsData.slices)
+	defer freeByteSliceArray(sideloadsData)
 	C.machineExecutionConfigSetSideloads(conf, sideloadsData)
 
 	C.machineExecutionConfigSetStopOnSideload(conf, boolToCInt(stopOnSideload))
diff --git a/packages/arb-avm-cpp/cmachine/utils.go b/packages/arb-avm-cpp/cmachine/utils.go
index bc0e3b3c20..5c57f29967 100644
--- a/packages/arb-avm-cpp/cmachine/utils.go
+++ b/packages/arb-avm-cpp/cmachine/utils.go
@@ -65,6 +65,25 @@ func receiveByteSliceArray(sliceArray C.ByteSliceArray) [][]byte {
 	return slices
 }
 
+// Note: the slices field of the returned struct needs manually freed by C.free
+func bytesArrayToByteSliceArray(bytes [][]byte) C.struct_ByteSliceArrayStruct {
+	byteSlices := encodeByteSliceList(bytes)
+	sliceArrayData := C.malloc(C.size_t(C.sizeof_struct_ByteSliceStruct * len(byteSlices)))
+	sliceArray := (*[1 << 30]C.struct_ByteSliceStruct)(sliceArrayData)[:len(byteSlices):len(byteSlices)]
+	for i, data := range byteSlices {
+		sliceArray[i] = data
+	}
+	return C.struct_ByteSliceArrayStruct{slices: sliceArrayData, count: C.int(len(byteSlices))}
+}
+
+func freeByteSliceArray(sliceArray C.struct_ByteSliceArrayStruct) {
+	dataSlices := (*[1 << 30]C.struct_ByteSliceStruct)(unsafe.Pointer(sliceArray.slices))[:sliceArray.count:sliceArray.count]
+	for _, slice := range dataSlices {
+		C.free(slice.data)
+	}
+	C.free(sliceArray.slices)
+}
+
 func toByteSliceView(data []byte) C.ByteSlice {
 	return C.struct_ByteSliceStruct{data: C.CBytes(data), length: C.int(len(data))}
 }