diff --git a/lib/hostip.c b/lib/hostip.c
index 7146bb2bf6d4d01aa2cae18cb6d2b8142e42d4f7..2deab34e40ef1069a02892537bdd1e83fa43b8f6 100644
--- a/lib/hostip.c
+++ b/lib/hostip.c
@@ -552,9 +552,9 @@ struct curl_hash *Curl_mk_dnscache(void)
  * returns a pointer to the malloc()ed copy. You need to call free() on the
  * returned buffer when you're done with it.
  */
-Curl_addrinfo *Curl_addrinfo_copy(void *org, int port)
+Curl_addrinfo *Curl_addrinfo_copy(const void *org, int port)
 {
-  struct hostent *orig = org;
+  const struct hostent *orig = org;
 
   return Curl_he2ai(orig, port);
 }
diff --git a/lib/hostip.h b/lib/hostip.h
index bd3b28dc5476ff8f8b9fa50f8d640fe9fb48ed05..72906ab3227757154be76b511484b723cde21462 100644
--- a/lib/hostip.h
+++ b/lib/hostip.h
@@ -224,13 +224,13 @@ Curl_addrinfo *Curl_ip2addr(in_addr_t num, const char *hostname, int port);
 
 /* [ipv4 only] Curl_he2ai() converts a struct hostent to a Curl_addrinfo chain
    and returns it */
-Curl_addrinfo *Curl_he2ai(struct hostent *, int port);
+Curl_addrinfo *Curl_he2ai(const struct hostent *, int port);
 
 /* relocate a hostent struct */
 void Curl_hostent_relocate(struct hostent *h, long offset);
 
 /* Clone a Curl_addrinfo struct, works protocol independently */
-Curl_addrinfo *Curl_addrinfo_copy(void *orig, int port);
+Curl_addrinfo *Curl_addrinfo_copy(const void *orig, int port);
 
 /*
  * Curl_printable_address() returns a printable version of the 1st address
diff --git a/lib/hostip4.c b/lib/hostip4.c
index 627b0783a287d7e33d351bf865299b3070c92e4d..c56f08a4e3202bb0528a2751b97c4ba767ab4220 100644
--- a/lib/hostip4.c
+++ b/lib/hostip4.c
@@ -400,7 +400,7 @@ Curl_addrinfo *Curl_getaddrinfo(struct connectdata *conn,
  *     #define h_addr  h_addr_list[0]
  */
 
-Curl_addrinfo *Curl_he2ai(struct hostent *he, int port)
+Curl_addrinfo *Curl_he2ai(const struct hostent *he, int port)
 {
   Curl_addrinfo *ai;
   Curl_addrinfo *prevai = NULL;
diff --git a/lib/hostip6.c b/lib/hostip6.c
index 3d80166c17f788e2f038f80b1ec81a6e1aec8d3c..7c17a15764073ec25ee41c8eb10c38e93b7d9e31 100644
--- a/lib/hostip6.c
+++ b/lib/hostip6.c
@@ -104,10 +104,10 @@ void Curl_freeaddrinfo(Curl_addrinfo *p)
  * address. But this is an ipv6 build and then we don't copy the address, we
  * just return the same pointer!
  */
-Curl_addrinfo *Curl_addrinfo_copy(void *source, int port)
+Curl_addrinfo *Curl_addrinfo_copy(const void *orig, int port)
 {
   (void) port;
-  return source;
+  return (Curl_addrinfo*)orig;
 }
 #endif