--- src/chartype.h.orig	2019-04-02 14:07:48.072839008 +0200
+++ src/chartype.h	2019-04-02 14:08:17.924144370 +0200
@@ -29,24 +29,6 @@
 #ifndef _h_chartype_f
 #define _h_chartype_f
 
-/* Ideally we should also test the value of the define to see if it
- * supports non-BMP code points without requiring UTF-16, but nothing
- * seems to actually advertise this properly, despite Unicode 3.1 having
- * been around since 2001... */
-#if	!defined(__NetBSD__) && \
-	!defined(__sun) && \
-	!(defined(__APPLE__) && defined(__MACH__)) && \
-	!defined(__OpenBSD__) && \
-	!defined(__FreeBSD__) && \
-	!defined(__DragonFly__)
-#ifndef __STDC_ISO_10646__
-/* In many places it is assumed that the first 127 code points are ASCII
- * compatible, so ensure wchar_t indeed does ISO 10646 and not some other
- * funky encoding that could break us in weird and wonderful ways. */
-	#error wchar_t must store ISO 10646 characters
-#endif
-#endif
-
 /* Oh for a <uchar.h> with char32_t and __STDC_UTF_32__ in it...
  * ref: ISO/IEC DTR 19769
  */