diff --git a/stdarg.h b/stdarg.h
index 37cec19..d562d6d 100644
--- a/stdarg.h
+++ b/stdarg.h
@@ -10,5 +10,6 @@ typedef char *va_list;
 
 /* fix a buggy dependency on GCC in libio.h */
 typedef va_list __gnuc_va_list;
+#define _VA_LIST_DEFINED
 
 #endif