diff --git a/tools/keytools/sign.c b/tools/keytools/sign.c
index 04a201d7..d7d570d2 100644
--- a/tools/keytools/sign.c
+++ b/tools/keytools/sign.c
@@ -64,7 +64,7 @@ static inline int fp_truncate(FILE *f, size_t len)
     if (f == NULL)
         return -1;
     fd = _fileno(f);
-    return _chsize_s(fd, len);
+    return _chsize(fd, len);
 }
 #else
 #define HAVE_MMAP 1