Index: s3backer.h
--- s3backer.h.orig
+++ s3backer.h
@@ -93,7 +93,7 @@
 #include <zlib.h>
 #include <fuse.h>
 
-#if defined __APPLE__ || defined __FreeBSD__
+#if defined __APPLE__ || defined __FreeBSD__ || defined __OpenBSD__
 extern char **environ;
 #endif
 
