1 files changed, 2 insertions, 0 deletions
diff --git a/lib/if.h b/lib/if.h
index 897f2be239..fce6705c23 100644
--- a/lib/if.h
+++ b/lib/if.h
@@ -309,6 +309,8 @@ struct interface {
 	QOBJ_FIELDS;
 };
 
+extern int if_cmp_func(const struct interface *a, const struct interface *b);
+
 RB_HEAD(if_name_head, interface);
 RB_PROTOTYPE(if_name_head, interface, name_entry, if_cmp_func)
 RB_HEAD(if_index_head, interface);