diff --git a/src/rp2_common/lwip/CMakeLists.txt b/src/rp2_common/lwip/CMakeLists.txt
index 33a4ca6..a7a1efa 100644
--- a/src/rp2_common/lwip/CMakeLists.txt
+++ b/src/rp2_common/lwip/CMakeLists.txt
@@ -44,6 +44,36 @@ if (EXISTS ${LWIP_PATH}/${LWIP_TEST_PATH})
         ${LWIP_PATH}/src/core/ipv4/ip4_frag.c
         ${LWIP_PATH}/src/netif/ethernet.c
         ${LWIP_PATH}/src/netif/slipif.c
+        ${LWIP_PATH}/src/netif/ppp/auth.c
+        ${LWIP_PATH}/src/netif/ppp/ccp.c
+        ${LWIP_PATH}/src/netif/ppp/chap-md5.c
+        ${LWIP_PATH}/src/netif/ppp/chap_ms.c
+        ${LWIP_PATH}/src/netif/ppp/chap-new.c
+        ${LWIP_PATH}/src/netif/ppp/demand.c
+        ${LWIP_PATH}/src/netif/ppp/eap.c
+        ${LWIP_PATH}/src/netif/ppp/ecp.c
+        ${LWIP_PATH}/src/netif/ppp/eui64.c
+        ${LWIP_PATH}/src/netif/ppp/fsm.c
+        ${LWIP_PATH}/src/netif/ppp/ipcp.c
+        ${LWIP_PATH}/src/netif/ppp/ipv6cp.c
+        ${LWIP_PATH}/src/netif/ppp/lcp.c
+        ${LWIP_PATH}/src/netif/ppp/magic.c
+        ${LWIP_PATH}/src/netif/ppp/mppe.c
+        ${LWIP_PATH}/src/netif/ppp/multilink.c
+        ${LWIP_PATH}/src/netif/ppp/ppp.c
+        ${LWIP_PATH}/src/netif/ppp/pppapi.c
+        ${LWIP_PATH}/src/netif/ppp/pppcrypt.c
+        ${LWIP_PATH}/src/netif/ppp/pppoe.c
+        ${LWIP_PATH}/src/netif/ppp/pppol2tp.c
+        ${LWIP_PATH}/src/netif/ppp/pppos.c
+        ${LWIP_PATH}/src/netif/ppp/upap.c
+        ${LWIP_PATH}/src/netif/ppp/utils.c
+        ${LWIP_PATH}/src/netif/ppp/vj.c
+        ${LWIP_PATH}/src/netif/ppp/polarssl/arc4.c
+        ${LWIP_PATH}/src/netif/ppp/polarssl/des.c
+        ${LWIP_PATH}/src/netif/ppp/polarssl/md4.c
+        ${LWIP_PATH}/src/netif/ppp/polarssl/md5.c
+        ${LWIP_PATH}/src/netif/ppp/polarssl/sha1.c
         ${LWIP_PATH}/src/apps/http/httpd.c
         ${LWIP_PATH}/src/apps/http/fs.c
 
diff --git a/src/rp2_common/lwip/lwip_arch.c b/src/rp2_common/lwip/lwip_arch.c
index c97172f..84d1fb6 100644
--- a/src/rp2_common/lwip/lwip_arch.c
+++ b/src/rp2_common/lwip/lwip_arch.c
@@ -19,4 +19,8 @@ void sys_arch_unprotect(sys_prot_t pval) {
 /* lwip needs a millisecond time source, and the TinyUSB board support code has one available */
 uint32_t sys_now(void) {
     return to_ms_since_boot(get_absolute_time());
+}
+
+u32_t sys_jiffies(void) {
+    return time_us_32();
 }
\ No newline at end of file