diff --git a/configure b/configure
index 4f3aa447566..2abbeb27944 100755
--- a/configure
+++ b/configure
@@ -13307,7 +13307,7 @@ $as_echo "#define HAVE_STDBOOL_H 1" >>confdefs.h
 fi
 
 
-for ac_header in atomic.h copyfile.h execinfo.h getopt.h ifaddrs.h langinfo.h mbarrier.h sys/epoll.h sys/event.h sys/personality.h sys/prctl.h sys/procctl.h sys/signalfd.h sys/ucred.h termios.h ucred.h
+for ac_header in atomic.h copyfile.h execinfo.h getopt.h ifaddrs.h mbarrier.h sys/epoll.h sys/event.h sys/personality.h sys/prctl.h sys/procctl.h sys/signalfd.h sys/ucred.h termios.h ucred.h
 do :
   as_ac_Header=`$as_echo "ac_cv_header_$ac_header" | $as_tr_sh`
 ac_fn_c_check_header_mongrel "$LINENO" "$ac_header" "$as_ac_Header" "$ac_includes_default"
diff --git a/configure.ac b/configure.ac
index 049bc014911..c46ed2c591a 100644
--- a/configure.ac
+++ b/configure.ac
@@ -1447,7 +1447,6 @@ AC_CHECK_HEADERS(m4_normalize([
 	execinfo.h
 	getopt.h
 	ifaddrs.h
-	langinfo.h
 	mbarrier.h
 	sys/epoll.h
 	sys/event.h
diff --git a/meson.build b/meson.build
index cc176f11b5d..cd711c6d018 100644
--- a/meson.build
+++ b/meson.build
@@ -2394,7 +2394,6 @@ header_checks = [
   'execinfo.h',
   'getopt.h',
   'ifaddrs.h',
-  'langinfo.h',
   'mbarrier.h',
   'stdbool.h',
   'strings.h',
diff --git a/src/bin/pg_upgrade/pg_upgrade.c b/src/bin/pg_upgrade/pg_upgrade.c
index 99f3d4543e9..663235816f8 100644
--- a/src/bin/pg_upgrade/pg_upgrade.c
+++ b/src/bin/pg_upgrade/pg_upgrade.c
@@ -40,10 +40,6 @@
 
 #include <time.h>
 
-#ifdef HAVE_LANGINFO_H
-#include <langinfo.h>
-#endif
-
 #include "catalog/pg_class_d.h"
 #include "common/file_perm.h"
 #include "common/logging.h"
diff --git a/src/include/pg_config.h.in b/src/include/pg_config.h.in
index 0e9b108e667..979925cc2e2 100644
--- a/src/include/pg_config.h.in
+++ b/src/include/pg_config.h.in
@@ -238,9 +238,6 @@
 /* Define to 1 if you have the `kqueue' function. */
 #undef HAVE_KQUEUE
 
-/* Define to 1 if you have the <langinfo.h> header file. */
-#undef HAVE_LANGINFO_H
-
 /* Define to 1 if you have the `ldap_initialize' function. */
 #undef HAVE_LDAP_INITIALIZE
 
diff --git a/src/port/chklocale.c b/src/port/chklocale.c
index 8cb81c8640e..a0cc52c38df 100644
--- a/src/port/chklocale.c
+++ b/src/port/chklocale.c
@@ -19,7 +19,7 @@
 #include "postgres_fe.h"
 #endif
 
-#ifdef HAVE_LANGINFO_H
+#ifndef WIN32
 #include <langinfo.h>
 #endif
 
@@ -287,8 +287,6 @@ pg_codepage_to_encoding(UINT cp)
 #endif
 #endif							/* WIN32 */
 
-#if (defined(HAVE_LANGINFO_H) && defined(CODESET)) || defined(WIN32)
-
 /*
  * Given a setting for LC_CTYPE, return the Postgres ID of the associated
  * encoding, if we can determine it.  Return -1 if we can't determine it.
@@ -415,19 +413,3 @@ pg_get_encoding_from_locale(const char *ctype, bool write_message)
 	free(sys);
 	return -1;
 }
-#else							/* (HAVE_LANGINFO_H && CODESET) || WIN32 */
-
-/*
- * stub if no multi-language platform support
- *
- * Note: we could return -1 here, but that would have the effect of
- * forcing users to specify an encoding to initdb on such platforms.
- * It seems better to silently default to SQL_ASCII.
- */
-int
-pg_get_encoding_from_locale(const char *ctype, bool write_message)
-{
-	return PG_SQL_ASCII;
-}
-
-#endif							/* (HAVE_LANGINFO_H && CODESET) || WIN32 */