diff --git a/doc/mdns.txt b/doc/mdns.txt
index 3cbb1ba4..e3921359 100644
--- a/doc/mdns.txt
+++ b/doc/mdns.txt
@@ -4,7 +4,7 @@ Author: Erik Ekman
 
 
 Note! The MDNS responder does not have all features required by the standards.
-See notes in src/core/mdns.c for what is left. It is however usable in normal
+See notes in src/apps/mdns/mdns.c for what is left. It is however usable in normal
 cases - but watch out if many devices on the same network try to use the same
 host/service instance names.
 
@@ -17,7 +17,7 @@ MDNS supports using IPv4 only, v6 only, or v4+v6.
 
 To enable MDNS responder, set
   LWIP_MDNS = 1
-in lwipopts.h and add src/core/mdns.c to your list of files to build.
+in lwipopts.h and add src/apps/mdns/mdns.c to your list of files to build.
 
 The max number of services supported per netif is defined by MDNS_MAX_SERVICES,
 default is 1.
diff --git a/src/apps/mdns/mdns.c b/src/apps/mdns/mdns.c
index 8e1c5f99..c51f5571 100644
--- a/src/apps/mdns/mdns.c
+++ b/src/apps/mdns/mdns.c
@@ -1890,7 +1890,7 @@ mdns_resp_init(void)
  * @return ERR_OK if netif was added, an err_t otherwise
  */
 err_t
-mdns_resp_add_netif(struct netif *netif, char *hostname, u32_t dns_ttl)
+mdns_resp_add_netif(struct netif *netif, const char *hostname, u32_t dns_ttl)
 {
   err_t res;
 
@@ -1985,7 +1985,7 @@ mdns_resp_remove_netif(struct netif *netif)
  * @return ERR_OK if the service was added to the netif, an err_t otherwise
  */
 err_t
-mdns_resp_add_service(struct netif *netif, char *name, char *service, u16_t proto, u16_t port, u32_t dns_ttl, service_get_txt_fn_t txt_fn, void *txt_data)
+mdns_resp_add_service(struct netif *netif, const char *name, const char *service, u16_t proto, u16_t port, u32_t dns_ttl, service_get_txt_fn_t txt_fn, void *txt_data)
 {
   int i;
   int slot = -1;
@@ -2042,7 +2042,7 @@ mdns_resp_add_service(struct netif *netif, char *name, char *service, u16_t prot
  * @return ERR_OK if the string was added to the reply, an err_t otherwise
  */
 err_t
-mdns_resp_add_service_txtitem(struct mdns_service *service, char *txt, int txt_len)
+mdns_resp_add_service_txtitem(struct mdns_service *service, const char *txt, int txt_len)
 {
   LWIP_ASSERT("mdns_resp_add_service: service != NULL", service);
 
diff --git a/src/include/lwip/apps/mdns.h b/src/include/lwip/apps/mdns.h
index 36892192..08fa5df7 100644
--- a/src/include/lwip/apps/mdns.h
+++ b/src/include/lwip/apps/mdns.h
@@ -47,12 +47,12 @@ struct mdns_service;
 
 void mdns_resp_init(void);
 
-err_t mdns_resp_add_netif(struct netif *netif, char *hostname, u32_t dns_ttl);
+err_t mdns_resp_add_netif(struct netif *netif, const char *hostname, u32_t dns_ttl);
 err_t mdns_resp_remove_netif(struct netif *netif);
 
 typedef void (*service_get_txt_fn_t)(struct mdns_service *service, void *txt_userdata);
-err_t mdns_resp_add_service(struct netif *netif, char *name, char *service, u16_t proto, u16_t port, u32_t dns_ttl, service_get_txt_fn_t txt_fn, void *txt_userdata);
-err_t mdns_resp_add_service_txtitem(struct mdns_service *service, char *txt, int txt_len);
+err_t mdns_resp_add_service(struct netif *netif, const char *name, const char *service, u16_t proto, u16_t port, u32_t dns_ttl, service_get_txt_fn_t txt_fn, void *txt_userdata);
+err_t mdns_resp_add_service_txtitem(struct mdns_service *service, const char *txt, int txt_len);
 
 
 /* Domain struct and methods - visible for unit tests */