diff --git a/src/msvc/msvc_compat.h b/src/msvc/msvc_compat.h
index 58a26f21..19acf5b8 100644
--- a/src/msvc/msvc_compat.h
+++ b/src/msvc/msvc_compat.h
@@ -32,6 +32,8 @@
 #pragma comment(lib, "ws2_32.lib")
 #pragma comment(lib, "setupapi.lib")
 
+#define F_OK 0
+
 #define PATH_MAX _MAX_PATH
 
 #define __builtin_popcount __popcnt