diff --git a/core/lib/petsciiconv.c b/core/lib/petsciiconv.c
index 873c7c2c7..a6eda5979 100644
--- a/core/lib/petsciiconv.c
+++ b/core/lib/petsciiconv.c
@@ -72,14 +72,13 @@ static unsigned char ascii2petscii[128] = {
   0x58,0x59,0x5a,0xdb,0xdd,0xdd,0x5e,0xdf,
 };
 
-static unsigned int i;
-static unsigned char *ptr;
-
 /*-----------------------------------------------------------------------------------*/
 void
 petsciiconv_toascii(char *buf, unsigned int len)
 {
-  static char c;
+  unsigned int i;
+  char *ptr;
+  char c;
   
   ptr = buf;
   for(i = len; i > 0; --i) {
@@ -108,6 +107,9 @@ petsciiconv_toascii(char *buf, unsigned int len)
 void
 petsciiconv_topetscii(char *buf, unsigned int len)
 {
+  unsigned int i;
+  char *ptr;
+
   ptr = buf;
   for(i = len; i > 0; --i) {
     *ptr = ascii2petscii[*ptr & 0x7f];
diff --git a/core/net/ip/resolv.c b/core/net/ip/resolv.c
index 4a9999cca..58bda004d 100644
--- a/core/net/ip/resolv.c
+++ b/core/net/ip/resolv.c
@@ -787,7 +787,7 @@ newdata(void)
 
   static int8_t i;
 
-  register struct namemap *namemapptr;
+  register struct namemap *namemapptr = NULL;
 
   struct dns_answer *ans;
 
diff --git a/core/net/ip/slipdev.c b/core/net/ip/slipdev.c
index caab454ac..8bc688557 100644
--- a/core/net/ip/slipdev.c
+++ b/core/net/ip/slipdev.c
@@ -103,7 +103,7 @@ slipdev_send(void)
   ptr = &uip_buf[UIP_LLH_LEN];
   for(i = 0; i < uip_len; ++i) {
     if(i == UIP_TCPIP_HLEN) {
-      ptr = (char *)uip_appdata;
+      ptr = (uint8_t *)uip_appdata;
     }
     c = *ptr++;
     switch(c) {
diff --git a/core/net/ip/uip-nameserver.c b/core/net/ip/uip-nameserver.c
index 6ced6b91e..367fe421d 100644
--- a/core/net/ip/uip-nameserver.c
+++ b/core/net/ip/uip-nameserver.c
@@ -56,8 +56,10 @@ typedef struct uip_nameserver_record {
   uint32_t lifetime;
 } uip_nameserver_record;
 
+#if UIP_NAMESERVER_POOL_SIZE > 1
 /** \brief Initialization flag */
 static uint8_t initialized = 0;
+#endif
 
 /** \name List and memory block
  * @{
diff --git a/core/net/ipv6/uip-nd6.c b/core/net/ipv6/uip-nd6.c
index 701f458fa..72b1badfa 100644
--- a/core/net/ipv6/uip-nd6.c
+++ b/core/net/ipv6/uip-nd6.c
@@ -116,17 +116,20 @@ void uip_log(char *msg);
 #define UIP_ND6_OPT_RDNSS_BUF ((uip_nd6_opt_dns *)&uip_buf[uip_l2_l3_icmp_hdr_len + nd6_opt_offset])
 /** @} */
 
+#if UIP_ND6_SEND_NA || UIP_ND6_SEND_RA || !UIP_CONF_ROUTER
 static uint8_t nd6_opt_offset;                     /** Offset from the end of the icmpv6 header to the option in uip_buf*/
 static uint8_t *nd6_opt_llao;   /**  Pointer to llao option in uip_buf */
+static uip_ds6_nbr_t *nbr; /**  Pointer to a nbr cache entry*/
+static uip_ds6_defrt_t *defrt; /**  Pointer to a router list entry */
+static uip_ds6_addr_t *addr; /**  Pointer to an interface address */
+#endif /* UIP_ND6_SEND_NA || UIP_ND6_SEND_RA || !UIP_CONF_ROUTER */
 
 #if !UIP_CONF_ROUTER            // TBD see if we move it to ra_input
 static uip_nd6_opt_prefix_info *nd6_opt_prefix_info; /**  Pointer to prefix information option in uip_buf */
 static uip_ipaddr_t ipaddr;
 static uip_ds6_prefix_t *prefix; /**  Pointer to a prefix list entry */
 #endif
-static uip_ds6_nbr_t *nbr; /**  Pointer to a nbr cache entry*/
-static uip_ds6_defrt_t *defrt; /**  Pointer to a router list entry */
-static uip_ds6_addr_t *addr; /**  Pointer to an interface address */
+
 /*------------------------------------------------------------------*/
 /* create a llao */ 
 static void
@@ -141,7 +144,7 @@ create_llao(uint8_t *llao, uint8_t type) {
 
 /*------------------------------------------------------------------*/
 
-
+#if UIP_ND6_SEND_NA
 static void
 ns_input(void)
 {
@@ -321,7 +324,7 @@ discard:
   uip_len = 0;
   return;
 }
-
+#endif /* UIP_ND6_SEND_NA */
 
 
 /*------------------------------------------------------------------*/
@@ -387,6 +390,7 @@ uip_nd6_ns_output(uip_ipaddr_t * src, uip_ipaddr_t * dest, uip_ipaddr_t * tgt)
   PRINTF("\n");
   return;
 }
+#if UIP_ND6_SEND_NA
 /*------------------------------------------------------------------*/
 /**
  * Neighbor Advertisement Processing
@@ -556,7 +560,7 @@ discard:
   uip_len = 0;
   return;
 }
-
+#endif /* UIP_ND6_SEND_NA */
 
 #if UIP_CONF_ROUTER
 #if UIP_ND6_SEND_RA
@@ -859,7 +863,7 @@ ra_input(void)
                               (uip_lladdr_t *)&nd6_opt_llao[UIP_ND6_OPT_DATA_OFFSET],
 			      1, NBR_STALE);
       } else {
-        uip_lladdr_t *lladdr = uip_ds6_nbr_get_ll(nbr);
+        uip_lladdr_t *lladdr = (uip_lladdr_t *)uip_ds6_nbr_get_ll(nbr);
         if(nbr->state == NBR_INCOMPLETE) {
           nbr->state = NBR_STALE;
         }
diff --git a/core/net/mac/contikimac/contikimac.c b/core/net/mac/contikimac/contikimac.c
index d5882845c..32cc65bbf 100644
--- a/core/net/mac/contikimac/contikimac.c
+++ b/core/net/mac/contikimac/contikimac.c
@@ -341,7 +341,6 @@ powercycle(struct rtimer *t, void *ptr)
 
   while(1) {
     static uint8_t packet_seen;
-    static rtimer_clock_t t0;
     static uint8_t count;
 
 #if SYNC_CYCLE_STARTS
@@ -365,7 +364,6 @@ powercycle(struct rtimer *t, void *ptr)
     packet_seen = 0;
 
     for(count = 0; count < CCA_COUNT_MAX; ++count) {
-      t0 = RTIMER_NOW();
       if(we_are_sending == 0 && we_are_receiving_burst == 0) {
         powercycle_turn_radio_on();
         /* Check if a packet is seen in the air. If so, we keep the
@@ -666,11 +664,12 @@ send_packet(mac_callback_t mac_callback, void *mac_callback_ptr,
 
     {
       rtimer_clock_t wt;
-      rtimer_clock_t txtime;
-      int ret;
-
-      txtime = RTIMER_NOW();
-      ret = NETSTACK_RADIO.transmit(transmit_len);
+      rtimer_clock_t txtime = RTIMER_NOW();
+#if RDC_CONF_HARDWARE_ACK
+      int ret = NETSTACK_RADIO.transmit(transmit_len);
+#else
+      NETSTACK_RADIO.transmit(transmit_len);
+#endif
 
 #if RDC_CONF_HARDWARE_ACK
      /* For radios that block in the transmit routine and detect the
diff --git a/core/net/mac/nullrdc.c b/core/net/mac/nullrdc.c
index 07915b186..111211a2b 100644
--- a/core/net/mac/nullrdc.c
+++ b/core/net/mac/nullrdc.c
@@ -264,11 +264,13 @@ send_list(mac_callback_t sent, void *ptr, struct rdc_buf_list *buf_list)
 static void
 packet_input(void)
 {
+#if NULLRDC_SEND_802154_ACK
   int original_datalen;
   uint8_t *original_dataptr;
 
   original_datalen = packetbuf_datalen();
   original_dataptr = packetbuf_dataptr();
+#endif
 
 #if NULLRDC_802154_AUTOACK
   if(packetbuf_datalen() == ACK_LEN) {
diff --git a/examples/ipv6/rpl-collect/udp-sender.c b/examples/ipv6/rpl-collect/udp-sender.c
index f216cbdcc..dd279cc7f 100644
--- a/examples/ipv6/rpl-collect/udp-sender.c
+++ b/examples/ipv6/rpl-collect/udp-sender.c
@@ -137,7 +137,7 @@ collect_common_send(void)
         /* Use parts of the IPv6 address as the parent address, in reversed byte order. */
         parent.u8[LINKADDR_SIZE - 1] = nbr->ipaddr.u8[sizeof(uip_ipaddr_t) - 2];
         parent.u8[LINKADDR_SIZE - 2] = nbr->ipaddr.u8[sizeof(uip_ipaddr_t) - 1];
-        parent_etx = rpl_get_parent_rank((linkaddr_t *) uip_ds6_nbr_get_ll(nbr)) / 2;
+        parent_etx = rpl_get_parent_rank((uip_lladdr_t *) uip_ds6_nbr_get_ll(nbr)) / 2;
       }
     }
     rtmetric = dag->rank;