--- jam.h.orig	Fri Apr 21 17:09:04 2006
+++ jam.h	Fri Apr 21 17:12:06 2006
@@ -290,6 +290,11 @@
 # define OS_NETBSD
 # define NO_VFORK
 # endif
+# ifdef __OpenBSD__
+# define unix
+# define OSMINOR "OS=OPENBSD"
+# define OS_OPENBSD
+# endif
 # ifdef __QNX__
 # ifdef __QNXNTO__
 # define OSMINOR "OS=QNXNTO"
@@ -388,6 +393,7 @@
      !defined(OS_NEXT) && \
      !defined(OS_MACHTEN) && \
      !defined(OS_MACOSX) && \
+     !defined(OS_OPENBSD) && \
      !defined(OS_RHAPSODY) && \
      !defined(OS_MVS)
 # include <malloc.h>
