diff --git a/apps/meteor/app/lib/server/functions/processWebhookMessage.ts b/apps/meteor/app/lib/server/functions/processWebhookMessage.ts
index bbf61fec6f4b..7529a9cdbaeb 100644
--- a/apps/meteor/app/lib/server/functions/processWebhookMessage.ts
+++ b/apps/meteor/app/lib/server/functions/processWebhookMessage.ts
@@ -33,6 +33,13 @@ type DefaultValues = {
 	emoji: string;
 };
 
+const toArray = (value: string | Array<string>): Array<string> => {
+	if (typeof value === 'string') {
+		return [value];
+	}
+	return value;
+};
+
 export const processWebhookMessage = async function (
 	messageObj: Payload,
 	user: IUser & { username: RequiredField<IUser, 'username'> },
@@ -40,7 +47,7 @@ export const processWebhookMessage = async function (
 ) {
 	const sentData = [];
 
-	const channels: Array<string> = [...new Set(messageObj.channel || messageObj.roomId || defaultValues.channel)];
+	const channels: Array<string> = [...new Set(toArray(messageObj.channel || messageObj.roomId || defaultValues.channel))];
 
 	for await (const channel of channels) {
 		const channelType = channel[0];