diff --git a/config.h.example b/config.h.example
index 1a5e626..22309cb 100644
--- a/config.h.example
+++ b/config.h.example
@@ -34,4 +34,4 @@
  * How many hours back should `ocat' display data by default
  */
 
-#DEFAULT_HISTORY_HOURS 6
+#define DEFAULT_HISTORY_HOURS 6