diff --git a/3rdparty/openvr/openvr_capi.h b/3rdparty/openvr/openvr_capi.h
index c01389cb6..230cd3b45 100644
--- a/3rdparty/openvr/openvr_capi.h
+++ b/3rdparty/openvr/openvr_capi.h
@@ -17,7 +17,11 @@
 #define EXTERN_C
 #endif
 
-#define OPENVR_FNTABLE_CALLTYPE __stdcall
+#if defined( _WIN32 )
+#	define OPENVR_FNTABLE_CALLTYPE __stdcall
+#else
+#	define OPENVR_FNTABLE_CALLTYPE
+#endif //
 
 // OPENVR API export macro
 #if defined( _WIN32 ) && !defined( _X360 )
@@ -44,11 +48,6 @@
 
 #include <stdint.h>
 
-#if defined( __WIN32 )
-typedef char bool;
-#endif
-
-
 // OpenVR Constants
 
 static const unsigned int k_unTrackingStringSize = 32;