--- original/os_internal.c	Sun Dec 31 22:41:44 2006
+++ os_internal.c	Fri May 18 01:49:29 2007
@@ -178,7 +178,7 @@ int os_setenv(const char *name, const char *value, int
 
 int os_unsetenv(const char *name)
 {
-#if defined(__FreeBSD__) || defined(__NetBSD__)
+#if defined(__FreeBSD__) || defined(__NetBSD__) || defined(__OpenBSD__)
 	unsetenv(name);
 	return 0;
 #else
