Index: EnginePl/obj_chain.h
--- EnginePl/obj_chain.h.orig
+++ EnginePl/obj_chain.h
@@ -95,7 +95,7 @@ static PlLong obj_chain_start = (PlLong) OBJ_CTOR;
 
 
 
-#if (defined(_MSC_VER) || defined(M_darwin)) && !defined(OBJ_CHAIN_REVERSE_ORDER)
+#if (defined(_MSC_VER) || defined(M_darwin) || defined(__OpenBSD__)) && !defined(OBJ_CHAIN_REVERSE_ORDER)
 #define OBJ_CHAIN_REVERSE_ORDER
 #endif