diff --git a/lib/zclient.h b/lib/zclient.h
index 03a6e0a..d18cf62 100644
--- a/lib/zclient.h
+++ b/lib/zclient.h
@@ -109,7 +109,7 @@
 void zclient_stop (struct zclient *);
 void zclient_reset (struct zclient *);
 int zclient_socket ();
-int zclient_socket_un (char *);
+int zclient_socket_un (const char *);
 
 void zclient_redistribute (int, struct zclient *, int);
 void zclient_redistribute_default (int, struct zclient *);