diff --git a/zdefs.acs b/zdefs.acs
index ac8fc81..72f55df 100644
--- a/zdefs.acs
+++ b/zdefs.acs
@@ -964,6 +964,7 @@
 #define SECF_DMGTERRAINFX	128
 #define SECF_DMGENDGODMODE 256
 #define SECF_DMGENDLEVEL 512
+#define SECF_DMGHAZARD 1024
 
 #define BLOCKF_CREATURES 1
 #define BLOCKF_MONSTERS 2