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
@@ -161,6 +161,15 @@ extern long ptrtoabs();
 #endif
 #endif
 
+/* OpenBSD */
+#ifdef __OpenBSD__
+#if __BYTE_ORDER == __LITTLE_ENDIAN
+#define XL_LITTLE_ENDIAN
+#else
+#define XL_BIG_ENDIAN
+#endif
+#endif
+
 /* Apple CC */
 #ifdef __APPLE__
 #define NNODES 2000
