diff --git a/ext/standard/string.c b/ext/standard/string.c
index c5c6520cf78..5d5f4324f54 100644
--- a/ext/standard/string.c
+++ b/ext/standard/string.c
@@ -197,8 +197,18 @@ PHPAPI struct lconv *localeconv_r(struct lconv *out)
 	tsrm_mutex_lock( locale_mutex );
 # endif
 
+#if defined(PHP_WIN32) && defined(ZTS)
+	{
+		/* Even with the enabled per thread locale, localeconv
+			won't check any locale change in the master thread. */
+		_locale_t cur = _get_current_locale();
+
+		res = cur->locinfo->lconv;
+	}
+#else
 	/* localeconv doesn't return an error condition */
 	res = localeconv();
+#endif
 
 	*out = *res;
 
diff --git a/ext/standard/tests/strings/bug65769.phpt b/ext/standard/tests/strings/bug65769.phpt
new file mode 100644
index 00000000000..15dad45bd5e
--- /dev/null
+++ b/ext/standard/tests/strings/bug65769.phpt
@@ -0,0 +1,80 @@
+--TEST--
+Bug #65769 localeconv() broken in TS builds
+--SKIPIF--
+<?php
+if (substr(PHP_OS, 0, 3) != 'WIN') {
+    die('skip Windows only');
+}
+?>
+--FILE--
+<?php
+
+$locales = array('sve', 'french', 'us', 'ru', 'czech', 'serbian');
+
+foreach ($locales as $locale) {
+	$locale = setlocale(LC_ALL, $locale);
+	$lconv = localeconv();
+	var_dump(
+		$locale,
+		$lconv['decimal_point'],
+		$lconv['thousands_sep'],
+		$lconv['int_curr_symbol'],
+		$lconv['currency_symbol'],
+		$lconv['mon_decimal_point'],
+		$lconv['mon_thousands_sep']
+	);
+	echo '++++++++++++++++++++++', "\n";
+}
+
+?>
++++DONE+++
+--EXPECTF--
+string(19) "Swedish_Sweden.1252"
+string(1) ","
+string(1) " "
+string(3) "SEK"
+string(2) "kr"
+string(1) ","
+string(1) "."
+++++++++++++++++++++++
+string(18) "French_France.1252"
+string(1) ","
+string(1) " "
+string(3) "EUR"
+string(1) "€"
+string(1) ","
+string(1) " "
+++++++++++++++++++++++
+string(26) "English_United States.1252"
+string(1) "."
+string(1) ","
+string(3) "USD"
+string(1) "$"
+string(1) "."
+string(1) ","
+++++++++++++++++++++++
+string(2) "ru"
+string(1) ","
+string(1) " "
+string(3) "RUB"
+string(1) "?"
+string(1) ","
+string(1) " "
+++++++++++++++++++++++
+string(25) "Czech_Czech Republic.1250"
+string(1) ","
+string(1) " "
+string(3) "CZK"
+string(2) "Kč"
+string(1) ","
+string(1) " "
+++++++++++++++++++++++
+string(19) "Serbian_Serbia.1250"
+string(1) ","
+string(1) "."
+string(3) "RSD"
+string(4) "din."
+string(1) ","
+string(1) "."
+++++++++++++++++++++++
++++DONE+++