--- ./courier-unicode.h.in.orig	2016-03-15 15:34:19.000000000 +0100
+++ ./courier-unicode.h.in	2016-03-15 15:34:53.000000000 +0100
@@ -41,6 +41,9 @@
 extern const char *unicode_locale_chset();
 
 #if @LANGINFO_L@
+#include <langinfo.h>
+#include <xlocale.h>
+
 extern const char *unicode_locale_chset_l(locale_t l);
 #endif