diff --git a/cpu/native/include/native_internal.h b/cpu/native/include/native_internal.h
index 7a2a8c3885..bee8fccdfc 100644
--- a/cpu/native/include/native_internal.h
+++ b/cpu/native/include/native_internal.h
@@ -150,8 +150,8 @@ extern volatile int _native_sigpend;
 extern volatile int _native_in_isr;
 extern volatile int _native_in_syscall;
 
-extern char __isr_stack[SIGSTKSZ];
-extern char __end_stack[SIGSTKSZ];
+extern char __isr_stack[];
+extern char __end_stack[];
 extern ucontext_t native_isr_context;
 extern ucontext_t end_context;
 extern ucontext_t *_native_cur_ctx, *_native_isr_ctx;
diff --git a/cpu/native/native_cpu.c b/cpu/native/native_cpu.c
index 5fb6241628..e4c02fd52a 100644
--- a/cpu/native/native_cpu.c
+++ b/cpu/native/native_cpu.c
@@ -170,7 +170,7 @@ void cpu_switch_context_exit(void)
         irq_disable();
         _native_in_isr = 1;
         native_isr_context.uc_stack.ss_sp = __isr_stack;
-        native_isr_context.uc_stack.ss_size = sizeof(__isr_stack);
+        native_isr_context.uc_stack.ss_size = SIGSTKSZ;
         native_isr_context.uc_stack.ss_flags = 0;
         makecontext(&native_isr_context, isr_cpu_switch_context_exit, 0);
         if (setcontext(&native_isr_context) == -1) {