Index: src/common/Patch.cpp
--- src/common/Patch.cpp.orig
+++ src/common/Patch.cpp
@@ -15,7 +15,7 @@
 #ifndef __LIBRETRO__
 
 #ifdef __GNUC__
-#if defined(__APPLE__) || defined(BSD) || defined(__NetBSD__)
+#if defined(__APPLE__) || defined(BSD) || defined(__NetBSD__) || defined(__OpenBSD__)
 typedef off_t __off64_t; /* off_t is 64 bits on BSD. */
 #define fseeko64 fseeko
 #define ftello64 ftello