diff --git a/isisd/isisd.c b/isisd/isisd.c
index 3fbed0b..af05cd1 100644
--- a/isisd/isisd.c
+++ b/isisd/isisd.c
@@ -60,7 +60,7 @@
 #endif /* TOPOLOGY_GENERATE */
 
 struct isis *isis = NULL;
-struct thread_master *master;
+extern struct thread_master *master;
 
 void
 isis_new (unsigned long process_id)