diff --git a/src/publishers/dlobPublisher.ts b/src/publishers/dlobPublisher.ts
index 479ac26..9b01bdb 100644
--- a/src/publishers/dlobPublisher.ts
+++ b/src/publishers/dlobPublisher.ts
@@ -24,6 +24,7 @@ import {
 	SubscriberLookup,
 	getPhoenixSubscriber,
 	getSerumSubscriber,
+	parsePositiveIntArray,
 	sleep,
 } from '../utils/utils';
 import {
@@ -72,12 +73,12 @@ const WS_FALLBACK_FETCH_INTERVAL = 10_000;
 
 // comma separated list of perp market indexes to load: i.e. 0,1,2,3
 const PERP_MARKETS_TO_LOAD = process.env.PERP_MARKETS_TO_LOAD
-	? process.env.PERP_MARKETS_TO_LOAD.split(',').map((m) => parseInt(m))
+	? parsePositiveIntArray(process.env.PERP_MARKETS_TO_LOAD)
 	: undefined;
 
 // comma separated list of spot market indexes to load: i.e. 0,1,2,3
 const SPOT_MARKETS_TO_LOAD = process.env.SPOT_MARKETS_TO_LOAD
-	? process.env.SPOT_MARKETS_TO_LOAD.split(',').map((m) => parseInt(m))
+	? parsePositiveIntArray(process.env.SPOT_MARKETS_TO_LOAD)
 	: undefined;
 
 logger.info(`RPC endpoint: ${endpoint}`);
diff --git a/src/utils/utils.ts b/src/utils/utils.ts
index 7d6e966..5f9db01 100644
--- a/src/utils/utils.ts
+++ b/src/utils/utils.ts
@@ -39,6 +39,17 @@ export function sleep(ms: number): Promise<void> {
 	return new Promise((resolve) => setTimeout(resolve, ms));
 }
 
+export function parsePositiveIntArray(
+	intArray: string,
+	separator = ','
+): number[] {
+	return intArray
+		.split(separator)
+		.map((s) => s.trim())
+		.map((s) => parseInt(s))
+		.filter((n) => !isNaN(n) && n > 0);
+}
+
 export const getOracleForMarket = (
 	driftClient: DriftClient,
 	marketType: MarketType,