diff --git a/os/common/ports/AVR/chcore.c b/os/common/ports/AVR/chcore.c
index 77f6ace9f..c754244c5 100644
--- a/os/common/ports/AVR/chcore.c
+++ b/os/common/ports/AVR/chcore.c
@@ -71,6 +71,9 @@ __attribute__((naked, weak))
 #endif
 void _port_switch(thread_t *ntp, thread_t *otp) {
 
+  (void)ntp;
+  (void)otp;
+
   asm volatile ("push    r2");
   asm volatile ("push    r3");
   asm volatile ("push    r4");