diff --git a/ospfd/ospf_spf.h b/ospfd/ospf_spf.h
index c1316e4..c9c539a 100644
--- a/ospfd/ospf_spf.h
+++ b/ospfd/ospf_spf.h
@@ -64,4 +64,17 @@
 
 /* void ospf_spf_calculate_timer_add (); */
 
+/* What triggered the SPF ? Can have at most 32 reasons with this */
+#define SPF_FLAG_ROUTER_LSA_INSTALL 0x1
+#define SPF_FLAG_NETWORK_LSA_INSTALL 0x2
+#define SPF_FLAG_SUMMARY_LSA_INSTALL 0x4
+#define SPF_FLAG_ASBR_SUMMARY_LSA_INSTALL 0x8
+#define SPF_FLAG_MAXAGE 0x10
+#define SPF_FLAG_ABR_STATUS_CHANGE 0x20
+#define SPF_FLAG_ASBR_STATUS_CHANGE 0x40
+#define SPF_FLAG_MAX_VALUE 0x40	/* Update this when adding flags */
+#define SPF_FLAG_MISC 0x1000000	/* Keep this last */
+
+extern void ospf_flag_spf_reason (unsigned int reason);
+
 #endif /* _QUAGGA_OSPF_SPF_H */