diff --git a/options/ansi/include/inttypes.h b/options/ansi/include/inttypes.h
index 45c5d2e43..b30fee872 100644
--- a/options/ansi/include/inttypes.h
+++ b/options/ansi/include/inttypes.h
@@ -117,6 +117,7 @@
 
 #define SCNd32 "d"
 #define SCNd64 __PRI64 "d"
+#define SCNdFAST64 __PRI64 "d"
 
 #define SCNu16 "hu"