http://austingroupbugs.net/view.php?id=162#c665

Index: lib-src/libnyquist/nyquist/xlisp/xlisp.h
--- lib-src/libnyquist/nyquist/xlisp/xlisp.h.orig
+++ lib-src/libnyquist/nyquist/xlisp/xlisp.h
@@ -173,7 +173,7 @@ extern long ptrtoabs();
 #endif
 
 /* FreeBSD */
-#ifdef FreeBSD
+#if defined(__FreeBSD__) || defined(__OpenBSD__)
 #if BYTE_ORDER == LITTLE_ENDIAN
 #define XL_LITTLE_ENDIAN
 #else
