diff --git a/code/__defines/mobs.dm b/code/__defines/mobs.dm
index e4e406d219a..63f52544020 100644
--- a/code/__defines/mobs.dm
+++ b/code/__defines/mobs.dm
@@ -58,7 +58,8 @@
 #define ROBOT 8
 #define SLIME 16
 #define SIMPLE_ANIMAL 32
-#define ALLMOBS (HUMAN|MONKEY|ALIEN|ROBOT|SLIME|SIMPLE_ANIMAL)
+#define HEAVY 64
+#define ALLMOBS (HUMAN|MONKEY|ALIEN|ROBOT|SLIME|SIMPLE_ANIMAL|HEAVY)
 
 #define NEXT_MOVE_DELAY 8