diff --git a/test_conformance/printf/util_printf.c b/test_conformance/printf/util_printf.c
index dbf604a7..31e58169 100644
--- a/test_conformance/printf/util_printf.c
+++ b/test_conformance/printf/util_printf.c
@@ -18,10 +18,6 @@
 #include "test_printf.h"
 
 
-#if defined (_WIN32)
-#define strtoull _strtoi64
-#endif
-
 const char* strType[] = {"int","float","octal","unsigned","hexadecimal","char","string","vector","address space"};