diff --git a/pcsx2/pcsx2hostfs.cpp b/pcsx2/pcsx2hostfs.cpp
index b369ecca1c..87ba70bac4 100644
--- a/pcsx2/pcsx2hostfs.cpp
+++ b/pcsx2/pcsx2hostfs.cpp
@@ -46,7 +46,11 @@
 u32 functionId;
 u32 paramsAddress;
 u32 paramsLength;
-u32 returnValue;
+u32 returnValue;
+
+#ifndef O_BINARY
+# define O_BINARY 0
+#endif
 
 #define IOP_RDONLY	0x0001
 #define IOP_WRONLY	0x0002