diff --git a/include/linux/signal.h b/include/linux/signal.h
index 706a499..200ed96 100644
--- a/include/linux/signal.h
+++ b/include/linux/signal.h
@@ -40,7 +40,7 @@ enum siginfo_layout {
 	SIL_SYS,
 };
 
-enum siginfo_layout siginfo_layout(int sig, int si_code);
+enum siginfo_layout siginfo_layout(unsigned sig, int si_code);
 
 /*
  * Define some primitives to manipulate sigset_t.