diff --git a/drivers/net/wireless/ath/ath9k/htc_hst.c b/drivers/net/wireless/ath/ath9k/htc_hst.c
index fe62ff668f75..99667aba289d 100644
--- a/drivers/net/wireless/ath/ath9k/htc_hst.c
+++ b/drivers/net/wireless/ath/ath9k/htc_hst.c
@@ -114,7 +114,13 @@ static void htc_process_conn_rsp(struct htc_target *target,
 
 	if (svc_rspmsg->status == HTC_SERVICE_SUCCESS) {
 		epid = svc_rspmsg->endpoint_id;
-		if (epid < 0 || epid >= ENDPOINT_MAX)
+
+		/* Check that the received epid for the endpoint to attach
+		 * a new service is valid. ENDPOINT0 can't be used here as it
+		 * is already reserved for HTC_CTRL_RSVD_SVC service and thus
+		 * should not be modified.
+		 */
+		if (epid <= ENDPOINT0 || epid >= ENDPOINT_MAX)
 			return;
 
 		service_id = be16_to_cpu(svc_rspmsg->service_id);