diff --git a/lib/defines.h b/lib/defines.h
index 08483940..6b1bb3cb 100644
--- a/lib/defines.h
+++ b/lib/defines.h
@@ -22,7 +22,7 @@ typedef unsigned char _Bool;
 # define __bool_true_false_are_defined 1
 #endif
 
-#define ISDIGIT_LOCALE(c) (IN_CTYPE_DOMAIN (c) && isdigit (c))
+#define ISDIGIT_LOCALE(c) isdigit (c)
 
 /* Take care of NLS matters.  */
 #ifdef S_SPLINT_S
diff --git a/libmisc/getdate.y b/libmisc/getdate.y
index 9b9f48c2..ce2235fd 100644
--- a/libmisc/getdate.y
+++ b/libmisc/getdate.y
@@ -31,12 +31,10 @@
 #include <ctype.h>
 #include <time.h>
 
-#define IN_CTYPE_DOMAIN(c) 1
-
-#define ISSPACE(c) (IN_CTYPE_DOMAIN (c) && isspace (c))
-#define ISALPHA(c) (IN_CTYPE_DOMAIN (c) && isalpha (c))
-#define ISUPPER(c) (IN_CTYPE_DOMAIN (c) && isupper (c))
-#define ISDIGIT_LOCALE(c) (IN_CTYPE_DOMAIN (c) && isdigit (c))
+#define ISSPACE(c) isspace (c)
+#define ISALPHA(c) isalpha (c)
+#define ISUPPER(c) isupper (c)
+#define ISDIGIT_LOCALE(c) isdigit (c)
 
 /* ISDIGIT differs from ISDIGIT_LOCALE, as follows:
    - Its arg may be any int or unsigned int; it need not be an unsigned char.