diff --git a/components/net/lwip/port/lwipopts.h b/components/net/lwip/port/lwipopts.h
index 8c6c9cfcc2..7f34333247 100644
--- a/components/net/lwip/port/lwipopts.h
+++ b/components/net/lwip/port/lwipopts.h
@@ -585,7 +585,7 @@
 #endif
 
 /* MEMP_NUM_SYS_TIMEOUT: the number of simulateously active timeouts. */
-#define MEMP_NUM_SYS_TIMEOUT       (LWIP_TCP + IP_REASSEMBLY + LWIP_ARP + (2*LWIP_DHCP) + LWIP_AUTOIP + LWIP_IGMP + LWIP_DNS + PPP_SUPPORT)
+#define MEMP_NUM_SYS_TIMEOUT       (LWIP_TCP + IP_REASSEMBLY + LWIP_ARP + (2*LWIP_DHCP) + LWIP_AUTOIP + LWIP_IGMP + LWIP_DNS + 2*PPP_SUPPORT)
 
 /*
  * LWIP_COMPAT_SOCKETS==1: Enable BSD-style sockets functions names.