diff --git a/include/net.h b/include/net.h
index 2a37a43..13e335a 100644
--- a/include/net.h
+++ b/include/net.h
@@ -315,9 +315,9 @@
 void ethaddr_to_string(const u8 enetaddr[6], char *str);
 
 #ifdef CONFIG_NET_RESOLV
-IPaddr_t resolv(char *host);
+IPaddr_t resolv(const char *host);
 #else
-static inline IPaddr_t resolv(char *host)
+static inline IPaddr_t resolv(const char *host)
 {
 	IPaddr_t ip = 0;
 	string_to_ip(host, &ip);
diff --git a/net/dns.c b/net/dns.c
index 0e16ea2..5488e9f 100644
--- a/net/dns.c
+++ b/net/dns.c
@@ -59,7 +59,7 @@
 static int dns_state;
 static IPaddr_t dns_ip;
 
-static int dns_send(char *name)
+static int dns_send(const char *name)
 {
 	int ret;
 	struct header *header;
@@ -199,7 +199,7 @@
 		net_eth_to_udplen(packet));
 }
 
-IPaddr_t resolv(char *host)
+IPaddr_t resolv(const char *host)
 {
 	IPaddr_t ip;
 	const char *ns;