diff --git a/slirp/main.h b/slirp/main.h
index bf601e223d..1f3b84de92 100644
--- a/slirp/main.h
+++ b/slirp/main.h
@@ -31,7 +31,7 @@ extern char *exec_shell;
 extern u_int curtime;
 extern fd_set *global_readfds, *global_writefds, *global_xfds;
 extern struct in_addr loopback_addr;
-extern in_addr_t loopback_mask;
+extern unsigned long loopback_mask;
 extern char *username;
 extern char *socket_path;
 extern int towrite_max;
diff --git a/slirp/slirp.c b/slirp/slirp.c
index 9787104b3b..38e0a2193a 100644
--- a/slirp/slirp.c
+++ b/slirp/slirp.c
@@ -30,7 +30,7 @@
 /* host loopback address */
 struct in_addr loopback_addr;
 /* host loopback network mask */
-in_addr_t loopback_mask;
+unsigned long loopback_mask;
 
 /* emulated hosts use the MAC addr 52:55:IP:IP:IP:IP */
 static const uint8_t special_ethaddr[ETH_ALEN] = {