diff --git a/ospf6d/ospf6_spf.c b/ospf6d/ospf6_spf.c
index 47a655c..88e1285 100644
--- a/ospf6d/ospf6_spf.c
+++ b/ospf6d/ospf6_spf.c
@@ -639,7 +639,7 @@
     {
       if (IS_OSPF6_DEBUG_SPF(PROCESS) || IS_OSPF6_DEBUG_SPF (TIME))
         zlog_debug ("SPF: calculation timer is already scheduled: %p",
-                   ospf6->t_spf_calc);
+                    (void *)ospf6->t_spf_calc);
       return;
     }