--- Libc/Libc-320.1.3/internat/NXIsDigit.c
+++ Libc/Libc-498/internat/NXIsDigit.c
@@ -32,6 +32,6 @@
 {
 	FIXSIGNEDCHAR(c);
 	if (c < 256)
-		return ((unsigned int)((_NX_CTypeTable_ + 1)[c] & (_D)));
+		return ((unsigned int)((_NX_CTypeTable_ + 1)[c] & (_CTYPE_D)));
 	return 0;
 }