diff --git a/keepalived/include/vrrp_if.h b/keepalived/include/vrrp_if.h
index 2aa1faaa3b..c201b19d81 100644
--- a/keepalived/include/vrrp_if.h
+++ b/keepalived/include/vrrp_if.h
@@ -143,7 +143,7 @@ typedef enum if_lookup {
 } if_lookup_t;
 
 /* Global data */
-list garp_delay;
+extern list garp_delay;
 
 /* prototypes */
 extern interface_t *if_get_by_ifindex(ifindex_t);