diff --git a/src/server.c b/src/server.c
index 30045594..284c5554 100644
--- a/src/server.c
+++ b/src/server.c
@@ -220,7 +220,7 @@ static void server_recv_cb (EV_P_ ev_io *w, int revents) {
             // IP V4
             size_t in_addr_len = sizeof(struct in_addr);
             if (r > in_addr_len) {
-                inet_ntop(AF_INET, (void *)(server->buf + offset),
+                inet_ntop(AF_INET, (const void *)(server->buf + offset),
                         host, INET_ADDRSTRLEN);
                 offset += in_addr_len;
             }