diff --git a/configure b/configure
index 8f59c93ff9..56da7cdc73 100755
--- a/configure
+++ b/configure
@@ -19244,7 +19244,8 @@ fi
 
 
 
-for ac_func in cbrt dlopen fdatasync getifaddrs getpeerucred getrlimit memmove poll pstat readlink setproctitle setsid sigprocmask symlink sync_file_range towlower utime utimes wcstombs wcstombs_l
+
+for ac_func in cbrt dlopen fdatasync getifaddrs getpeerucred getrlimit mbstowcs_l memmove poll pstat readlink setproctitle setsid sigprocmask symlink sync_file_range towlower utime utimes wcstombs wcstombs_l
 do
 as_ac_var=`$as_echo "ac_cv_func_$ac_func" | $as_tr_sh`
 { $as_echo "$as_me:$LINENO: checking for $ac_func" >&5
diff --git a/configure.in b/configure.in
index 3acefa1797..8d02abb4cc 100644
--- a/configure.in
+++ b/configure.in
@@ -1200,7 +1200,7 @@ PGAC_VAR_INT_TIMEZONE
 AC_FUNC_ACCEPT_ARGTYPES
 PGAC_FUNC_GETTIMEOFDAY_1ARG
 
-AC_CHECK_FUNCS([cbrt dlopen fdatasync getifaddrs getpeerucred getrlimit memmove poll pstat readlink setproctitle setsid sigprocmask symlink sync_file_range towlower utime utimes wcstombs wcstombs_l])
+AC_CHECK_FUNCS([cbrt dlopen fdatasync getifaddrs getpeerucred getrlimit mbstowcs_l memmove poll pstat readlink setproctitle setsid sigprocmask symlink sync_file_range towlower utime utimes wcstombs wcstombs_l])
 
 AC_REPLACE_FUNCS(fseeko)
 case $host_os in
diff --git a/src/backend/utils/adt/pg_locale.c b/src/backend/utils/adt/pg_locale.c
index 92ea4413cc..297edd63e8 100644
--- a/src/backend/utils/adt/pg_locale.c
+++ b/src/backend/utils/adt/pg_locale.c
@@ -1206,17 +1206,17 @@ char2wchar(wchar_t *to, size_t tolen, const char *from, size_t fromlen,
 		else
 		{
 #ifdef HAVE_LOCALE_T
-#ifdef HAVE_WCSTOMBS_L
+#ifdef HAVE_MBSTOWCS_L
 			/* Use mbstowcs_l for nondefault locales */
 			result = mbstowcs_l(to, str, tolen, locale);
-#else							/* !HAVE_WCSTOMBS_L */
+#else							/* !HAVE_MBSTOWCS_L */
 			/* We have to temporarily set the locale as current ... ugh */
 			locale_t	save_locale = uselocale(locale);
 
 			result = mbstowcs(to, str, tolen);
 
 			uselocale(save_locale);
-#endif   /* HAVE_WCSTOMBS_L */
+#endif   /* HAVE_MBSTOWCS_L */
 #else							/* !HAVE_LOCALE_T */
 			/* Can't have locale != 0 without HAVE_LOCALE_T */
 			elog(ERROR, "mbstowcs_l is not available");
diff --git a/src/include/pg_config.h.in b/src/include/pg_config.h.in
index dbe28931f8..1ffb032835 100644
--- a/src/include/pg_config.h.in
+++ b/src/include/pg_config.h.in
@@ -333,6 +333,9 @@
 /* Define to 1 if `long long int' works and is 64 bits. */
 #undef HAVE_LONG_LONG_INT_64
 
+/* Define to 1 if you have the `mbstowcs_l' function. */
+#undef HAVE_MBSTOWCS_L
+
 /* Define to 1 if you have the `memmove' function. */
 #undef HAVE_MEMMOVE
 
diff --git a/src/include/pg_config.h.win32 b/src/include/pg_config.h.win32
index e6fc482534..b7b7c641d3 100644
--- a/src/include/pg_config.h.win32
+++ b/src/include/pg_config.h.win32
@@ -249,6 +249,9 @@
 #define HAVE_LONG_LONG_INT_64
 #endif
 
+/* Define to 1 if you have the `mbstowcs_l' function. */
+#define HAVE_MBSTOWCS_L 1
+
 /* Define to 1 if you have the `memmove' function. */
 #define HAVE_MEMMOVE 1