diff --git a/src/dlob-subscriber/DLOBSubscriberIO.ts b/src/dlob-subscriber/DLOBSubscriberIO.ts
index ee984c9..b67b1b4 100644
--- a/src/dlob-subscriber/DLOBSubscriberIO.ts
+++ b/src/dlob-subscriber/DLOBSubscriberIO.ts
@@ -10,6 +10,7 @@ import {
 import { RedisClient } from '../utils/redisClient';
 import {
 	SubscriberLookup,
+	addMarketSlotToResponse,
 	addOracletoResponse,
 	l2WithBNToStrings,
 } from '../utils/utils';
@@ -130,7 +131,13 @@ export class DLOBSubscriberIO extends DLOBSubscriber {
 			l2Args.marketType,
 			l2Args.marketIndex
 		);
-
+		addMarketSlotToResponse(
+			l2Formatted,
+			this.driftClient,
+			l2Args.marketType,
+			l2Args.marketIndex
+		);
+	
 		const l2Formatted_depth100 = Object.assign({}, l2Formatted, {
 			bids: l2Formatted.bids.slice(0, 100),
 			asks: l2Formatted.asks.slice(0, 100),
diff --git a/src/utils/utils.ts b/src/utils/utils.ts
index d8530ba..831a7fb 100644
--- a/src/utils/utils.ts
+++ b/src/utils/utils.ts
@@ -132,6 +132,21 @@ export const addOracletoResponse = (
 	}
 };
 
+export const addMarketSlotToResponse = (
+	response: L2OrderBook | L3OrderBook,
+	driftClient: DriftClient,
+	marketType: MarketType,
+	marketIndex: number
+): void => {
+	let marketSlot: number;
+	if (isVariant(marketType, 'perp')) {
+		marketSlot = driftClient.accountSubscriber.getMarketAccountAndSlot(marketIndex).slot;
+	} else {
+		marketSlot = driftClient.accountSubscriber.getSpotMarketAccountAndSlot(marketIndex).slot;
+	}
+	response['marketSlot'] = marketSlot;
+};
+
 /**
  * Takes in a req.query like: `{
  * 		marketName: 'SOL-PERP,BTC-PERP,ETH-PERP',