diff --git a/src/p_mobj.cpp b/src/p_mobj.cpp
index 6d8ce4418..e93b886e8 100644
--- a/src/p_mobj.cpp
+++ b/src/p_mobj.cpp
@@ -140,6 +140,7 @@ IMPLEMENT_POINTY_CLASS (AActor)
  DECLARE_POINTER (master)
  DECLARE_POINTER (Poisoner)
  DECLARE_POINTER (Damage)
+ DECLARE_POINTER (alternative)
 END_POINTERS
 
 AActor::~AActor ()