--- ../zlib-1.2.8/contrib/minizip/ioapi.h	2012-01-16 19:51:31.000000000 -0700
+++ zlib/contrib/minizip/ioapi.h	2017-11-11 09:05:50.662012999 -0700
@@ -50,7 +50,7 @@
 #define ftello64 ftell
 #define fseeko64 fseek
 #else
-#ifdef __FreeBSD__
+#if defined(__FreeBSD__) || defined(__OpenBSD__)
 #define fopen64 fopen
 #define ftello64 ftello
 #define fseeko64 fseeko
