diff --git a/mtr/net.c b/mtr/net.c

index bd7ee41..4c89185 100644

--- a/mtr/net.c

+++ b/mtr/net.c

@@ -201,6 +201,7 @@ extern int bitpattern;		/* packet bit pattern used by ping */

 extern int tos;			/* type of service set in ping packet*/

 extern int af;			/* address family of remote target */

 extern int mtrtype;		/* type of query packet used */

+ip_t unspec_addr;

 /* return the number of microseconds to wait before sending the next

    ping */

diff --git a/mtr/net.h b/mtr/net.h

index 6e2c172..bc6ca38 100644

--- a/mtr/net.h

+++ b/mtr/net.h

@@ -121,7 +121,7 @@ extern int fld_index[];

 extern unsigned char fld_active[];

 extern char available_options[];

-ip_t unspec_addr;

+extern ip_t unspec_addr;

 /* MPLS label object */

 struct mplslen {