1 files changed, 4 insertions, 0 deletions
diff --git a/util.c b/util.c
index 1030c3ecbe..f39e17b8b7 100644
--- a/util.c
+++ b/util.c
@@ -13,6 +13,10 @@
 # define MINGW_HAS_SECURE_API 1
 #endif
 
+#ifndef __STDC_WANT_LIB_EXT1__
+#define __STDC_WANT_LIB_EXT1__ 1
+#endif
+
 #include "ruby/internal/config.h"
 
 #include <ctype.h>