diff --git a/cpu/native/hwtimer_cpu.c b/cpu/native/hwtimer_cpu.c
index b63e0e42e3..c9419522a8 100644
--- a/cpu/native/hwtimer_cpu.c
+++ b/cpu/native/hwtimer_cpu.c
@@ -210,7 +210,10 @@ void hwtimer_arch_set_absolute(unsigned long value, short timer)
 {
     DEBUG("hwtimer_arch_set_absolute(%lu, %i)\n", value, timer);
     value -= native_hwtimer_now;
-    return(hwtimer_arch_set(value, timer));
+
+    hwtimer_arch_set(value, timer);
+
+    return;
 }
 
 unsigned long hwtimer_arch_now(void)
diff --git a/cpu/native/include/cpu.h b/cpu/native/include/cpu.h
index 484bafef40..0efb9c1d04 100644
--- a/cpu/native/include/cpu.h
+++ b/cpu/native/include/cpu.h
@@ -52,7 +52,7 @@ void eINT(void);
 /**
  * register interrupt handler handler for interrupt sig
  */
-int register_interrupt(int sig, void *handler);
+int register_interrupt(int sig, void (*handler)(void));
 
 /**
  * unregister interrupt handler for interrupt sig
diff --git a/cpu/native/irq_cpu.c b/cpu/native/irq_cpu.c
index 053d8eb5b7..6b6f2bf1d9 100644
--- a/cpu/native/irq_cpu.c
+++ b/cpu/native/irq_cpu.c
@@ -358,7 +358,7 @@ void native_isr_entry(int sig, siginfo_t *info, void *context)
  * TODO: use appropriate data structure for signal
  *       handlers.
  */
-int register_interrupt(int sig, void *handler)
+int register_interrupt(int sig, void (*handler)(void))
 {
     struct sigaction sa;
     DEBUG("XXX: register_interrupt()\n");
@@ -369,8 +369,7 @@ int register_interrupt(int sig, void *handler)
 
     native_irq_handlers[sig].func = handler;
 
-    sa.sa_sigaction = (void *) native_isr_entry;
-    /* sa.sa_handler = (void*) native_isr_entry; */
+    sa.sa_sigaction = native_isr_entry;
 
     if (sigemptyset(&sa.sa_mask) == -1) {
         err(1, "register_interrupt: sigemptyset");
@@ -402,7 +401,6 @@ int unregister_interrupt(int sig)
 
     native_irq_handlers[sig].func = NULL;
 
-    /* sa.sa_sigaction = SIG_IGN; */
     sa.sa_handler = SIG_IGN;
 
     if (sigemptyset(&sa.sa_mask) == -1) {
@@ -437,7 +435,7 @@ void native_interrupt_init(void)
         native_irq_handlers[i].func = NULL;
     }
 
-    sa.sa_sigaction = (void *) native_isr_entry;
+    sa.sa_sigaction = native_isr_entry;
 
     if (sigemptyset(&sa.sa_mask) == -1) {
         err(1, "native_interrupt_init: sigemptyset");
diff --git a/cpu/native/net/interface.c b/cpu/native/net/interface.c
index 9da1413cd0..aab38196fe 100644
--- a/cpu/native/net/interface.c
+++ b/cpu/native/net/interface.c
@@ -106,7 +106,7 @@ void nativenet_switch_to_rx()
 /* nativenet_internal.h *************************************************/
 /************************************************************************/
 
-int _nativenet_register_cb(int event, void *func)
+int _nativenet_register_cb(int event, void (*func)(void))
 {
     if (event > NNEV_MAXEV) {
         DEBUG("_nativenet_register_cb: event > NNEV_MAXEV");
diff --git a/cpu/native/rtc/posix-rtc.c b/cpu/native/rtc/posix-rtc.c
index 965de49186..88eaf7b9f5 100644
--- a/cpu/native/rtc/posix-rtc.c
+++ b/cpu/native/rtc/posix-rtc.c
@@ -48,6 +48,8 @@ void rtc_disable(void)
 void rtc_set_localtime(struct tm *localt)
 {
     DEBUG("rtc_set_localtime()\n");
+
+    (void)localt; /* not implemented atm */
     printf("setting time not supported.");
 }
 
diff --git a/cpu/native/startup.c b/cpu/native/startup.c
index 74f28f8b65..befc8a8e89 100644
--- a/cpu/native/startup.c
+++ b/cpu/native/startup.c
@@ -35,6 +35,9 @@ __attribute__((constructor)) static void startup(int argc, char **argv)
         printf("usage: %s <tap interface>\n", argv[0]);
         exit(EXIT_FAILURE);
     }
+#else /* args unused here */
+    (void) argc;
+    (void) argv;
 #endif
 
     native_cpu_init();