diff --git a/hints/openbsd.sh b/hints/openbsd.sh
index f364c9d3df4d..5c83f92847f2 100644
--- a/hints/openbsd.sh
+++ b/hints/openbsd.sh
@@ -155,6 +155,7 @@ esac
 # https://marc.info/?l=openbsd-bugs&m=155364568608759&w=2
 # which is being fixed.  In the meantime, forbid POSIX 2008 locales
 #d_newlocale="$undef"
+ccflags="$ccflags -DNO_LOCALE_NUMERIC -DNO_LOCALE_COLLATE -DNO_LOCALE_MONETARY -DNO_LOCALE_TIME -DNO_LOCALE_MESSAGES"
 
 # Seems that OpenBSD returns bogus values in _Thread_local variables in code in
 # shared objects, so we need to disable it. See GH #19109