diff --git a/ospfd/ospf_spf.c b/ospfd/ospf_spf.c
index f6260fb..564ae84 100644
--- a/ospfd/ospf_spf.c
+++ b/ospfd/ospf_spf.c
@@ -1171,7 +1171,7 @@
     }
   
   /* XXX Monotic timers: we only care about relative time here. */
-  timersub (&recent_time, &ospf->ts_spf, &result);
+  result = tv_sub (recent_time, ospf->ts_spf);
   
   elapsed = (result.tv_sec * 1000) + (result.tv_usec / 1000);
   ht = ospf->spf_holdtime * ospf->spf_hold_multiplier;