diff --git a/include/rpc/rpc.h b/include/rpc/rpc.h
index e16b4fd316f3..b770d75786b1 100644
--- a/include/rpc/rpc.h
+++ b/include/rpc/rpc.h
@@ -83,7 +83,7 @@ extern int get_myaddress __P((struct sockaddr_in *));
 extern int bindresvport __P((int, struct sockaddr_in *));
 extern int registerrpc __P((int, int, int, char *(*) __P((char [UDPMSGSIZE])),
     xdrproc_t, xdrproc_t));
-extern int callrpc __P((char *, int, int, int, xdrproc_t, void *,
+extern int callrpc __P((const char *, int, int, int, xdrproc_t, void *,
     xdrproc_t , void *));
 extern int getrpcport __P((char *, int, int, int));
 
diff --git a/lib/libc/rpc/rpc_soc.c b/lib/libc/rpc/rpc_soc.c
index 8df05290bf84..75dd1f2f7fae 100644
--- a/lib/libc/rpc/rpc_soc.c
+++ b/lib/libc/rpc/rpc_soc.c
@@ -332,7 +332,7 @@ get_myaddress(addr)
  */
 int
 callrpc(host, prognum, versnum, procnum, inproc, in, outproc, out)
-	char *host;
+	const char *host;
 	int prognum, versnum, procnum;
 	xdrproc_t inproc, outproc;
 	void *in, *out;