diff --git a/sys/net/sixlowpan/flowcontrol.c b/sys/net/sixlowpan/flowcontrol.c
index 0e5e1c9968..11ebe81e53 100644
--- a/sys/net/sixlowpan/flowcontrol.c
+++ b/sys/net/sixlowpan/flowcontrol.c
@@ -20,7 +20,7 @@ flowcontrol_stat_t slwin_stat;
 sem_t connection_established;
 int16_t synack_seqnum = -1;
 
-ipv6_addr_t init_threeway_handshake() {
+ipv6_addr_t init_threeway_handshake(void) {
     border_syn_packet_t *syn;
     msg_t m;
     m.content.ptr = NULL;
@@ -48,7 +48,7 @@ ipv6_addr_t init_threeway_handshake() {
     return addr;
 }
 
-ipv6_addr_t flowcontrol_init() {
+ipv6_addr_t flowcontrol_init(void) {
     int i;
     
     sem_init(&slwin_stat.send_win_not_full,BORDER_SWS);
diff --git a/sys/net/sixlowpan/flowcontrol.h b/sys/net/sixlowpan/flowcontrol.h
index 6c4c3ba582..060e049014 100644
--- a/sys/net/sixlowpan/flowcontrol.h
+++ b/sys/net/sixlowpan/flowcontrol.h
@@ -51,7 +51,7 @@ typedef struct __attribute__ ((packed)) border_syn_packet_t {
     ipv6_addr_t addr;
 } border_syn_packet_t;
 
-ipv6_addr_t flowcontrol_init();
+ipv6_addr_t flowcontrol_init(void);
 void flowcontrol_send_over_uart(border_packet_t *packet, int len);
 void flowcontrol_deliver_from_uart(border_packet_t *packet, int len);
 
diff --git a/sys/net/sixlowpan/rpl/objective_functions.c b/sys/net/sixlowpan/rpl/objective_functions.c
index 96cb486731..9eb637111d 100644
--- a/sys/net/sixlowpan/rpl/objective_functions.c
+++ b/sys/net/sixlowpan/rpl/objective_functions.c
@@ -1,6 +1,6 @@
 #include "objective_functions.h"
 
-void of0(){
+void of0(void){
 
 
 }
diff --git a/sys/net/sixlowpan/rpl/objective_functions.h b/sys/net/sixlowpan/rpl/objective_functions.h
index a6acfb0a3c..06c7b1620a 100644
--- a/sys/net/sixlowpan/rpl/objective_functions.h
+++ b/sys/net/sixlowpan/rpl/objective_functions.h
@@ -1,3 +1,3 @@
 #include <stdio.h>
 
-void of0();
+void of0(void);
diff --git a/sys/net/sixlowpan/rpl/of0.c b/sys/net/sixlowpan/rpl/of0.c
index aebb6b6ebc..2719dedd26 100644
--- a/sys/net/sixlowpan/rpl/of0.c
+++ b/sys/net/sixlowpan/rpl/of0.c
@@ -10,7 +10,7 @@ rpl_of_t rpl_of0 = {
 	NULL
 };
 
-rpl_of_t *rpl_get_of0(){
+rpl_of_t *rpl_get_of0(void){
 	return &rpl_of0;
 }
 
diff --git a/sys/net/sixlowpan/rpl/of0.h b/sys/net/sixlowpan/rpl/of0.h
index f31ec693e5..72a6900e8b 100644
--- a/sys/net/sixlowpan/rpl/of0.h
+++ b/sys/net/sixlowpan/rpl/of0.h
@@ -1,6 +1,6 @@
 #include "rpl_structs.h"
 
-rpl_of_t *rpl_get_of0();
+rpl_of_t *rpl_get_of0(void);
 uint16_t calc_rank(rpl_parent_t *, uint16_t);
 rpl_parent_t *which_parent(rpl_parent_t *, rpl_parent_t *);
 rpl_dodag_t *which_dodag(rpl_dodag_t *, rpl_dodag_t *);
diff --git a/sys/net/sixlowpan/rpl/rpl.c b/sys/net/sixlowpan/rpl/rpl.c
index 12c6b7f332..14d72486b3 100644
--- a/sys/net/sixlowpan/rpl/rpl.c
+++ b/sys/net/sixlowpan/rpl/rpl.c
@@ -65,18 +65,18 @@ static struct icmpv6_hdr_t * get_rpl_send_icmpv6_buf(uint8_t ext_len){
 	//return ((struct icmpv6_hdr_t*)&(rpl_send_buffer[LLHDR_IPV6HDR_LEN + ext_len]));
 	return ((struct icmpv6_hdr_t*)&(rpl_send_buffer[IPV6_HDR_LEN + ext_len]));
 }
-static struct rpl_dio_t* get_rpl_send_dio_buf(){
+static struct rpl_dio_t* get_rpl_send_dio_buf(void){
 	//return ((struct rpl_dio_t*)&(rpl_send_buffer[LLHDR_ICMPV6HDR_LEN]));
 	return ((struct rpl_dio_t*)&(rpl_send_buffer[IPV6HDR_ICMPV6HDR_LEN]));
 }
-static struct rpl_dao_t* get_rpl_send_dao_buf(){
+static struct rpl_dao_t* get_rpl_send_dao_buf(void){
 	//return ((struct rpl_dao_t*)&(rpl_send_buffer[LLHDR_ICMPV6HDR_LEN]));
 	return ((struct rpl_dao_t*)&(rpl_send_buffer[IPV6HDR_ICMPV6HDR_LEN]));
 }
-static struct rpl_dao_ack_t* get_rpl_send_dao_ack_buf(){
+static struct rpl_dao_ack_t* get_rpl_send_dao_ack_buf(void){
 	return ((struct rpl_dao_ack_t*)&(rpl_send_buffer[IPV6HDR_ICMPV6HDR_LEN]));
 }
-static struct rpl_dis_t* get_rpl_send_dis_buf(){
+static struct rpl_dis_t* get_rpl_send_dis_buf(void){
 	//return ((struct rpl_dis_t*)&(rpl_send_buffer[LLHDR_ICMPV6HDR_LEN]));
 	return ((struct rpl_dis_t*)&(rpl_send_buffer[IPV6HDR_ICMPV6HDR_LEN]));
 }
@@ -98,17 +98,17 @@ static struct rpl_opt_transit_t* get_rpl_send_opt_transit_buf(uint8_t rpl_msg_le
 static struct ipv6_hdr_t * get_rpl_ipv6_buf(void){
 	return ((struct ipv6_hdr_t*)&(rpl_buffer[0]));
 }
-static struct rpl_dio_t* get_rpl_dio_buf(){
+static struct rpl_dio_t* get_rpl_dio_buf(void){
 	return ((struct rpl_dio_t*)&(rpl_buffer[IPV6HDR_ICMPV6HDR_LEN]));
 }
 
-static struct rpl_dao_t* get_rpl_dao_buf(){
+static struct rpl_dao_t* get_rpl_dao_buf(void){
 	return ((struct rpl_dao_t*)&(rpl_buffer[IPV6HDR_ICMPV6HDR_LEN]));
 }
-static struct rpl_dao_ack_t* get_rpl_dao_ack_buf(){
+static struct rpl_dao_ack_t* get_rpl_dao_ack_buf(void){
 	return ((struct rpl_dao_ack_t*)&(buffer[LLHDR_ICMPV6HDR_LEN]));
 }
-static struct rpl_dis_t* get_rpl_dis_buf(){
+static struct rpl_dis_t* get_rpl_dis_buf(void){
 	return ((struct rpl_dis_t*)&(rpl_buffer[IPV6HDR_ICMPV6HDR_LEN]));
 }
 static struct rpl_opt_t* get_rpl_opt_buf(uint8_t rpl_msg_len){
@@ -188,7 +188,7 @@ uint8_t rpl_init(transceiver_type_t trans, uint16_t rpl_address){
 
 }
 
-void rpl_init_root(){
+void rpl_init_root(void){
 	rpl_instance_t *inst;
 	rpl_dodag_t *dodag;
 
@@ -293,7 +293,7 @@ void send_DIS(ipv6_addr_t *destination){
 	icmp_send_buf = get_rpl_send_icmpv6_buf(ipv6_ext_hdr_len);
 
 	icmp_send_buf->type = ICMP_RPL_CONTROL;
-	icmp_send_buf->code = ICMP_CODE_DIO;
+	icmp_send_buf->code = ICMP_CODE_DIS;
 	icmp_send_buf->checksum = ~icmpv6_csum(PROTO_NUM_ICMPV6);
 	
 	rpl_send_dis_buf = get_rpl_send_dis_buf();
@@ -892,7 +892,7 @@ rpl_routing_entry_t *rpl_find_routing_entry(ipv6_addr_t *addr){
 	return NULL;
 }
 
-void rpl_clear_routing_table(){
+void rpl_clear_routing_table(void){
 	for(uint8_t i=0; i<RPL_MAX_ROUTING_ENTRIES; i++){
 		memset(&routing_table[i], 0, sizeof(routing_table[i]));
 	}
diff --git a/sys/net/sixlowpan/rpl/rpl.h b/sys/net/sixlowpan/rpl/rpl.h
index 698a1fb9d7..ae62a8364b 100644
--- a/sys/net/sixlowpan/rpl/rpl.h
+++ b/sys/net/sixlowpan/rpl/rpl.h
@@ -9,7 +9,7 @@
 #define RPL_PROCESS_STACKSIZE 4096
 
 uint8_t rpl_init(transceiver_type_t trans, uint16_t rpl_address);
-void rpl_init_root();
+void rpl_init_root(void);
 rpl_of_t *rpl_get_of_for_ocp(uint16_t ocp);
 
 void send_DIO(ipv6_addr_t *destination);
@@ -26,5 +26,5 @@ ipv6_addr_t *rpl_get_next_hop(ipv6_addr_t * addr);
 void rpl_add_routing_entry(ipv6_addr_t *addr, ipv6_addr_t *next_hop, uint16_t lifetime);
 void rpl_del_routing_entry(ipv6_addr_t *addr);
 rpl_routing_entry_t * rpl_find_routing_entry(ipv6_addr_t *addr);
-void rpl_clear_routing_table();
+void rpl_clear_routing_table(void);
 rpl_routing_entry_t *rpl_get_routing_table(void);
diff --git a/sys/net/sixlowpan/rpl/rpl_dodag.h b/sys/net/sixlowpan/rpl/rpl_dodag.h
index 174628c911..19873f158f 100644
--- a/sys/net/sixlowpan/rpl/rpl_dodag.h
+++ b/sys/net/sixlowpan/rpl/rpl_dodag.h
@@ -3,17 +3,17 @@
 
 rpl_instance_t *rpl_new_instance(uint8_t instanceid);
 rpl_instance_t *rpl_get_instance(uint8_t instanceid);
-rpl_instance_t *rpl_get_my_instance();
+rpl_instance_t *rpl_get_my_instance(void);
 rpl_dodag_t *rpl_new_dodag(uint8_t instanceid, ipv6_addr_t *id);
 rpl_dodag_t *rpl_get_dodag(ipv6_addr_t *id);
-rpl_dodag_t *rpl_get_my_dodag();
+rpl_dodag_t *rpl_get_my_dodag(void);
 void rpl_join_dodag(rpl_dodag_t *dodag, ipv6_addr_t *parent, uint16_t parent_rank);
 void rpl_del_dodag(rpl_dodag_t *dodag);
 rpl_parent_t *rpl_new_parent(rpl_dodag_t *dodag, ipv6_addr_t *address, uint16_t rank);
 rpl_parent_t *rpl_find_parent(ipv6_addr_t *address);
 void rpl_leave_dodag(rpl_dodag_t * dodag);
 bool rpl_equal_id(ipv6_addr_t *id1, ipv6_addr_t *id2);
-ipv6_addr_t *rpl_get_my_preferred_parent();
+ipv6_addr_t *rpl_get_my_preferred_parent(void);
 void rpl_delete_parent(rpl_parent_t *parent);
 void rpl_delete_worst_parent(void);
 void rpl_delete_all_parents(void);
diff --git a/sys/net/sixlowpan/sixlowborder.h b/sys/net/sixlowpan/sixlowborder.h
index ada8333119..f2e790c7b7 100644
--- a/sys/net/sixlowpan/sixlowborder.h
+++ b/sys/net/sixlowpan/sixlowborder.h
@@ -12,7 +12,7 @@
 
 extern ipv6_addr_t abr_addr;
 
-uint16_t border_get_serial_reader();
+uint16_t border_get_serial_reader(void);
 
 uint8_t *get_serial_out_buffer(int offset);
 uint8_t *get_serial_in_buffer(int offset);
diff --git a/sys/net/sixlowpan/sixlownd.c b/sys/net/sixlowpan/sixlownd.c
index ed5be56b00..4cf52ff3f6 100644
--- a/sys/net/sixlowpan/sixlownd.c
+++ b/sys/net/sixlowpan/sixlownd.c
@@ -64,8 +64,8 @@ uint8_t recvd_cids_len = 0;
 plist_t *recvd_prefixes[OPT_PI_LIST_LEN];
 uint8_t recvd_pref_len = 0;
 
-static abr_cache_t* abr_get_most_current();
-static abr_cache_t* abr_get_oldest();
+static abr_cache_t* abr_get_most_current(void);
+static abr_cache_t* abr_get_oldest(void);
 
 int min(int a, int b) {
     if (a < b) {
@@ -1057,7 +1057,7 @@ void nbr_cache_rem(ipv6_addr_t *addr){
  * @return The most current authoritive border router information, NULL
  *         if no such information is given.
  */
-static abr_cache_t *abr_get_most_current(){
+static abr_cache_t *abr_get_most_current(void){
     abr_cache_t *abr = NULL;
     int i;
     int version = abr_cache[0].version;
@@ -1071,7 +1071,7 @@ static abr_cache_t *abr_get_most_current(){
     return abr;
 }
 
-static abr_cache_t *abr_get_oldest(){
+static abr_cache_t *abr_get_oldest(void){
     abr_cache_t *abr = NULL;
     int i;
     int version = abr_cache[0].version;
diff --git a/sys/net/sixlowpan/sixlowpan.c b/sys/net/sixlowpan/sixlowpan.c
index 028cc85408..abb635cdfa 100644
--- a/sys/net/sixlowpan/sixlowpan.c
+++ b/sys/net/sixlowpan/sixlowpan.c
@@ -212,14 +212,12 @@ void lowpan_transfer(void)
 	msg_t m_recv, m_send;
 	ipv6_hdr_t *ipv6_buf;
 	lowpan_reas_buf_t *current_buf;
-	long temp_time;
 	uint8_t gotosleep;
 
 	while (1)
 		{
-		temp_time = LONG_MAX;
-		gotosleep = 1;
 
+		gotosleep = 1;
 		mutex_lock(&fifo_mutex);
 		current_buf = packet_fifo;
 		if (current_buf != NULL)
diff --git a/sys/net/sixlowpan/sixlowpan.h b/sys/net/sixlowpan/sixlowpan.h
index 2d6da1760b..e8f9650777 100644
--- a/sys/net/sixlowpan/sixlowpan.h
+++ b/sys/net/sixlowpan/sixlowpan.h
@@ -72,13 +72,13 @@ void lowpan_iphc_encoding(ieee_802154_long_t *dest, ipv6_hdr_t *ipv6_buf_extra,
 void lowpan_iphc_decoding(uint8_t *data, uint8_t length,
                           ieee_802154_long_t *s_laddr,
                           ieee_802154_long_t *d_laddr);
-uint8_t lowpan_context_len();
+uint8_t lowpan_context_len(void);
 void add_fifo_packet(lowpan_reas_buf_t *current_packet);
 lowpan_context_t * lowpan_context_update(
                         uint8_t num, const ipv6_addr_t *prefix, 
                         uint8_t length, uint8_t comp,
                         uint16_t lifetime);
-lowpan_context_t * lowpan_context_get();
+lowpan_context_t * lowpan_context_get(void);
 lowpan_context_t * lowpan_context_lookup(ipv6_addr_t *addr);
 lowpan_context_t * lowpan_context_num_lookup(uint8_t num);
 lowpan_reas_buf_t *collect_garbage_fifo(lowpan_reas_buf_t *current_buf);