diff --git a/ospfd/ospf_spf.c b/ospfd/ospf_spf.c
index 58a3992..e1c290e 100644
--- a/ospfd/ospf_spf.c
+++ b/ospfd/ospf_spf.c
@@ -1290,7 +1290,7 @@
   area->ts_spf = area->ospf->ts_spf;
 
   if (IS_DEBUG_OSPF_EVENT)
-    zlog_debug ("ospf_spf_calculate: Stop. %ld vertices",
+    zlog_debug ("ospf_spf_calculate: Stop. %zd vertices",
                 mtype_stats_alloc(MTYPE_OSPF_VERTEX));
 
   /* Free SPF vertices, but not the list. List has ospf_vertex_free