diff --git a/pproxy.c b/pproxy.c
index 1bea6fb84..34e569bce 100644
--- a/pproxy.c
+++ b/pproxy.c
@@ -8,7 +8,7 @@
 #include "network.h"
 #include "proxy.h"
 
-Socket platform_new_connection(SockAddr addr, char *hostname,
+Socket platform_new_connection(SockAddr addr, const char *hostname,
 			       int port, int privport,
 			       int oobinline, int nodelay, int keepalive,
 			       Plug plug, Conf *conf)