diff --git a/src/osdep/win32/overrides.c b/src/osdep/win32/overrides.c
index be04991d..82d46336 100644
--- a/src/osdep/win32/overrides.c
+++ b/src/osdep/win32/overrides.c
@@ -8,6 +8,8 @@
 #include "config.h"
 #endif
 
+#define FD_SETSIZE 1024
+
 #define WIN32_OVERRIDES_SELF
 
 #include "osdep/system.h"