diff --git a/src/schedule.c b/src/schedule.c
index 2ec5842..a579b02 100644
--- a/src/schedule.c
+++ b/src/schedule.c
@@ -11,7 +11,7 @@ hexagram_schedule *hexagram_schedule_create(hexagram_table_entry *table,
         goto error_malloc_schedule;
     }
 
-    schedule->timer   = NULL;
+    schedule->timer   = 0;
     schedule->current = 0;
 
     for (i=0; i<count; i++) {