diff --git a/include/net/icmp.h b/include/net/icmp.h
index ce70a58..9ac2524 100644
--- a/include/net/icmp.h
+++ b/include/net/icmp.h
@@ -25,7 +25,7 @@
 
 struct icmp_err {
   int		errno;
-  unsigned	fatal:1;
+  unsigned int	fatal:1;
 };
 
 extern const struct icmp_err icmp_err_convert[];