diff --git a/contrib/ports/unix/port/sys_arch.c b/contrib/ports/unix/port/sys_arch.c
index 113ac58b..bfebf324 100644
--- a/contrib/ports/unix/port/sys_arch.c
+++ b/contrib/ports/unix/port/sys_arch.c
@@ -73,11 +73,11 @@ get_monotonic_time(struct timespec *ts)
 {
 #ifdef LWIP_UNIX_MACH
   /* darwin impl (no CLOCK_MONOTONIC) */
-  uint64_t t = mach_absolute_time();
+  u64_t t = mach_absolute_time();
   mach_timebase_info_data_t timebase_info = {0, 0};
   mach_timebase_info(&timebase_info);
-  uint64_t nano = (t * timebase_info.numer) / (timebase_info.denom);
-  uint64_t sec = nano/1000000000L;
+  u64_t nano = (t * timebase_info.numer) / (timebase_info.denom);
+  u64_t sec = nano/1000000000L;
   nano -= sec * 1000000000L;
   ts->tv_sec = sec;
   ts->tv_nsec = nano;
diff --git a/src/apps/altcp_tls/altcp_tls_mbedtls.c b/src/apps/altcp_tls/altcp_tls_mbedtls.c
index ba8cce49..770e1dde 100644
--- a/src/apps/altcp_tls/altcp_tls_mbedtls.c
+++ b/src/apps/altcp_tls/altcp_tls_mbedtls.c
@@ -100,10 +100,10 @@ struct altcp_tls_config {
   mbedtls_ctr_drbg_context ctr_drbg;
   mbedtls_x509_crt *cert;
   mbedtls_pk_context *pkey;
-  uint8_t cert_count;
-  uint8_t cert_max;
-  uint8_t pkey_count;
-  uint8_t pkey_max;
+  u8_t cert_count;
+  u8_t cert_max;
+  u8_t pkey_count;
+  u8_t pkey_max;
   mbedtls_x509_crt *ca;
 #if defined(MBEDTLS_SSL_CACHE_C) && ALTCP_MBEDTLS_USE_SESSION_CACHE
   /** Inter-connection cache for fast connection startup */
@@ -661,7 +661,7 @@ altcp_mbedtls_debug(void *ctx, int level, const char *file, int line, const char
  * ATTENTION: Server certificate and private key have to be added outside this function!
  */
 static struct altcp_tls_config *
-altcp_tls_create_config(int is_server, uint8_t cert_count, uint8_t pkey_count, int have_ca)
+altcp_tls_create_config(int is_server, u8_t cert_count, u8_t pkey_count, int have_ca)
 {
   size_t sz;
   int ret;
@@ -756,7 +756,7 @@ altcp_tls_create_config(int is_server, uint8_t cert_count, uint8_t pkey_count, i
   return conf;
 }
 
-struct altcp_tls_config *altcp_tls_create_config_server(uint8_t cert_count)
+struct altcp_tls_config *altcp_tls_create_config_server(u8_t cert_count)
 {
   struct altcp_tls_config *conf = altcp_tls_create_config(1, cert_count, cert_count, 0);
   if (conf == NULL) {
diff --git a/src/core/tcp.c b/src/core/tcp.c
index 8bfcc530..d6bead6c 100644
--- a/src/core/tcp.c
+++ b/src/core/tcp.c
@@ -2594,7 +2594,7 @@ tcp_ext_arg_alloc_id(void)
  * @param callbacks callback table (const since it is referenced, not copied!)
  */
 void
-tcp_ext_arg_set_callbacks(struct tcp_pcb *pcb, uint8_t id, const struct tcp_ext_arg_callbacks * const callbacks)
+tcp_ext_arg_set_callbacks(struct tcp_pcb *pcb, u8_t id, const struct tcp_ext_arg_callbacks * const callbacks)
 {
   LWIP_ASSERT("pcb != NULL", pcb != NULL);
   LWIP_ASSERT("id < LWIP_TCP_PCB_NUM_EXT_ARGS", id < LWIP_TCP_PCB_NUM_EXT_ARGS);
@@ -2613,7 +2613,7 @@ tcp_ext_arg_set_callbacks(struct tcp_pcb *pcb, uint8_t id, const struct tcp_ext_
  * @param id ext_args index to set (allocated via @ref tcp_ext_arg_alloc_id)
  * @param arg data pointer to set
  */
-void tcp_ext_arg_set(struct tcp_pcb *pcb, uint8_t id, void *arg)
+void tcp_ext_arg_set(struct tcp_pcb *pcb, u8_t id, void *arg)
 {
   LWIP_ASSERT("pcb != NULL", pcb != NULL);
   LWIP_ASSERT("id < LWIP_TCP_PCB_NUM_EXT_ARGS", id < LWIP_TCP_PCB_NUM_EXT_ARGS);
@@ -2631,7 +2631,7 @@ void tcp_ext_arg_set(struct tcp_pcb *pcb, uint8_t id, void *arg)
  * @param id ext_args index to set (allocated via @ref tcp_ext_arg_alloc_id)
  * @return data pointer at the given index
  */
-void *tcp_ext_arg_get(const struct tcp_pcb *pcb, uint8_t id)
+void *tcp_ext_arg_get(const struct tcp_pcb *pcb, u8_t id)
 {
   LWIP_ASSERT("pcb != NULL", pcb != NULL);
   LWIP_ASSERT("id < LWIP_TCP_PCB_NUM_EXT_ARGS", id < LWIP_TCP_PCB_NUM_EXT_ARGS);
diff --git a/src/include/lwip/altcp_tls.h b/src/include/lwip/altcp_tls.h
index 87b2761e..94da12f6 100644
--- a/src/include/lwip/altcp_tls.h
+++ b/src/include/lwip/altcp_tls.h
@@ -63,7 +63,7 @@ struct altcp_tls_config;
 /** @ingroup altcp_tls
  * Create an ALTCP_TLS server configuration handle prepared for multiple certificates
  */
-struct altcp_tls_config *altcp_tls_create_config_server(uint8_t cert_count);
+struct altcp_tls_config *altcp_tls_create_config_server(u8_t cert_count);
 
 /** @ingroup altcp_tls
  * Add a certificate to an ALTCP_TLS server configuration handle
diff --git a/src/include/lwip/tcp.h b/src/include/lwip/tcp.h
index daf75994..6e7c0148 100644
--- a/src/include/lwip/tcp.h
+++ b/src/include/lwip/tcp.h
@@ -486,9 +486,9 @@ err_t            tcp_tcp_get_tcp_addrinfo(struct tcp_pcb *pcb, int local, ip_add
 
 #if LWIP_TCP_PCB_NUM_EXT_ARGS
 u8_t tcp_ext_arg_alloc_id(void);
-void tcp_ext_arg_set_callbacks(struct tcp_pcb *pcb, uint8_t id, const struct tcp_ext_arg_callbacks * const callbacks);
-void tcp_ext_arg_set(struct tcp_pcb *pcb, uint8_t id, void *arg);
-void *tcp_ext_arg_get(const struct tcp_pcb *pcb, uint8_t id);
+void tcp_ext_arg_set_callbacks(struct tcp_pcb *pcb, u8_t id, const struct tcp_ext_arg_callbacks * const callbacks);
+void tcp_ext_arg_set(struct tcp_pcb *pcb, u8_t id, void *arg);
+void *tcp_ext_arg_get(const struct tcp_pcb *pcb, u8_t id);
 #endif
 
 #ifdef __cplusplus
diff --git a/src/include/netif/lowpan6_ble.h b/src/include/netif/lowpan6_ble.h
index 5190e7bc..ff35fcd3 100644
--- a/src/include/netif/lowpan6_ble.h
+++ b/src/include/netif/lowpan6_ble.h
@@ -66,8 +66,8 @@ err_t rfc7668_if_init(struct netif *netif);
 err_t tcpip_rfc7668_input(struct pbuf *p, struct netif *inp);
 #endif
 
-void ble_addr_to_eui64(uint8_t *dst, const uint8_t *src, int public_addr);
-void eui64_to_ble_addr(uint8_t *dst, const uint8_t *src);
+void ble_addr_to_eui64(u8_t *dst, const u8_t *src, int public_addr);
+void eui64_to_ble_addr(u8_t *dst, const u8_t *src);
 
 #ifdef __cplusplus
 }
diff --git a/src/netif/lowpan6.c b/src/netif/lowpan6.c
index 7f0d2767..58aa15a8 100644
--- a/src/netif/lowpan6.c
+++ b/src/netif/lowpan6.c
@@ -679,7 +679,7 @@ lowpan6_input(struct pbuf *p, struct netif *netif)
     /* check for duplicate */
     lrh = lowpan6_data.reass_list;
     while (lrh != NULL) {
-      uint8_t discard = 0;
+      u8_t discard = 0;
       lrh_next = lrh->next_packet;
       if ((lrh->sender_addr.addr_len == src.addr_len) &&
           (memcmp(lrh->sender_addr.addr, src.addr, src.addr_len) == 0)) {
diff --git a/src/netif/lowpan6_ble.c b/src/netif/lowpan6_ble.c
index d59b432f..f13da80d 100644
--- a/src/netif/lowpan6_ble.c
+++ b/src/netif/lowpan6_ble.c
@@ -107,7 +107,7 @@ static struct lowpan6_link_addr rfc7668_peer_addr;
  * @see LWIP_RFC7668_LINUX_WORKAROUND_PUBLIC_ADDRESS
  */
 void
-ble_addr_to_eui64(uint8_t *dst, const uint8_t *src, int public_addr)
+ble_addr_to_eui64(u8_t *dst, const u8_t *src, int public_addr)
 {
   /* according to RFC7668 ch 3.2.2. */
   memcpy(dst, src, 3);
@@ -136,7 +136,7 @@ ble_addr_to_eui64(uint8_t *dst, const uint8_t *src, int public_addr)
  *
  */
 void
-eui64_to_ble_addr(uint8_t *dst, const uint8_t *src)
+eui64_to_ble_addr(u8_t *dst, const u8_t *src)
 {
   /* according to RFC7668 ch 3.2.2. */
   memcpy(dst,src,3);
@@ -386,7 +386,7 @@ rfc7668_input(struct pbuf * p, struct netif *netif)
       if ((i%4)==0) {
         LWIP_DEBUGF(LWIP_RFC7668_IP_UNCOMPRESSED_DEBUG, ("\n"));
       }
-      LWIP_DEBUGF(LWIP_RFC7668_IP_UNCOMPRESSED_DEBUG, ("%2X ", *((uint8_t *)p->payload+i)));
+      LWIP_DEBUGF(LWIP_RFC7668_IP_UNCOMPRESSED_DEBUG, ("%2X ", *((u8_t *)p->payload+i)));
     }
     LWIP_DEBUGF(LWIP_RFC7668_IP_UNCOMPRESSED_DEBUG, ("\np->len: %d\n", p->len));
   }