diff --git a/src/auth.c b/src/auth.c
index 066a9e4..dd46566 100644
--- a/src/auth.c
+++ b/src/auth.c
@@ -31,7 +31,7 @@
 	  if (!(flag & F_IPV4))
 	    continue;
 	  
-	  netmask.s_addr = htonl(~((1 << (32 - subnet->prefixlen)) - 1));
+	  netmask.s_addr = htonl(~(in_addr_t)0 << (32 - subnet->prefixlen));
 	  
 	  if  (is_same_net(addr, subnet->addr.addr.addr4, netmask))
 	    return subnet;
diff --git a/src/netlink.c b/src/netlink.c
index cff43cc..b393283 100644
--- a/src/netlink.c
+++ b/src/netlink.c
@@ -208,7 +208,8 @@
 		    struct in_addr netmask, addr, broadcast;
 		    char *label = NULL;
 
-		    netmask.s_addr = htonl(0xffffffff << (32 - ifa->ifa_prefixlen));
+		    netmask.s_addr = htonl(~(in_addr_t)0 << (32 - ifa->ifa_prefixlen));
+
 		    addr.s_addr = 0;
 		    broadcast.s_addr = 0;