diff --git a/newlib/libc/signal/sig2str.c b/newlib/libc/signal/sig2str.c
index d3be1ba68..f4df913e2 100644
--- a/newlib/libc/signal/sig2str.c
+++ b/newlib/libc/signal/sig2str.c
@@ -226,7 +226,7 @@ sig2str(int signum, char *str)
 }
 
 int
-str2sig(const char *restrict str, int *restrict pnum)
+str2sig(const char *__restrict str, int *__restrict pnum)
 {
   unsigned long j = 0;
   char *endp;