diff --git a/ext/standard/basic_functions.stub.php b/ext/standard/basic_functions.stub.php
index 740d3014f26a7..b7be370bb4777 100644
--- a/ext/standard/basic_functions.stub.php
+++ b/ext/standard/basic_functions.stub.php
@@ -2555,8 +2555,8 @@ function nl2br(string $string, bool $use_xhtml = true): string {}
 function strip_tags(string $string, array|string|null $allowed_tags = null): string {}
 
 /**
- * @param array|string $locales
- * @param string $rest
+ * @param array|string|null $locales
+ * @param string|null $rest
  */
 function setlocale(int $category, $locales, ...$rest): string|false {}
 
diff --git a/ext/standard/basic_functions_arginfo.h b/ext/standard/basic_functions_arginfo.h
index 8655941fe4ce7..c49e229cd6c0b 100644
--- a/ext/standard/basic_functions_arginfo.h
+++ b/ext/standard/basic_functions_arginfo.h
@@ -1,5 +1,5 @@
 /* This is a generated file, edit the .stub.php file instead.
- * Stub hash: f8c3745d39ed21f29f46b47f15b6fd1178e55dbb */
+ * Stub hash: b9958c8f2f643e072ba7c6ee33ad238ea8dd702e */
 
 ZEND_BEGIN_ARG_WITH_RETURN_TYPE_INFO_EX(arginfo_set_time_limit, 0, 1, _IS_BOOL, 0)
 	ZEND_ARG_TYPE_INFO(0, seconds, IS_LONG, 0)
diff --git a/ext/standard/string.c b/ext/standard/string.c
index 75be1f1dcab1c..4bc56f550fe1b 100644
--- a/ext/standard/string.c
+++ b/ext/standard/string.c
@@ -4937,17 +4937,18 @@ PHP_FUNCTION(setlocale)
 	zend_string **strings = do_alloca(sizeof(zend_string *) * num_args, use_heap);
 
 	for (uint32_t i = 0; i < num_args; i++) {
-		if (UNEXPECTED(Z_TYPE(args[i]) != IS_ARRAY && !zend_parse_arg_str(&args[i], &strings[i], false, i + 2))) {
+		if (UNEXPECTED(Z_TYPE(args[i]) != IS_ARRAY && !zend_parse_arg_str(&args[i], &strings[i], true, i + 2))) {
 			zend_wrong_parameter_type_error(i + 2, Z_EXPECTED_ARRAY_OR_STRING, &args[i]);
 			goto out;
 		}
 	}
 
 	for (uint32_t i = 0; i < num_args; i++) {
+		zend_string *result;
 		if (Z_TYPE(args[i]) == IS_ARRAY) {
 			zval *elem;
 			ZEND_HASH_FOREACH_VAL(Z_ARRVAL(args[i]), elem) {
-				zend_string *result = try_setlocale_zval(cat, elem);
+				result = try_setlocale_zval(cat, elem);
 				if (EG(exception)) {
 					goto out;
 				}
@@ -4956,15 +4957,18 @@ PHP_FUNCTION(setlocale)
 					goto out;
 				}
 			} ZEND_HASH_FOREACH_END();
+			continue;
+		} else if (Z_ISNULL(args[i])) {
+			result = try_setlocale_str(cat, ZSTR_EMPTY_ALLOC());
 		} else {
-			zend_string *result = try_setlocale_str(cat, strings[i]);
-			if (EG(exception)) {
-				goto out;
-			}
-			if (result) {
-				RETVAL_STR(result);
-				goto out;
-			}
+			result = try_setlocale_str(cat, strings[i]);
+		}
+		if (EG(exception)) {
+			goto out;
+		}
+		if (result) {
+			RETVAL_STR(result);
+			goto out;
 		}
 	}
 
diff --git a/ext/standard/tests/strings/gh18823_weak.phpt b/ext/standard/tests/strings/gh18823_weak.phpt
index bc9611098a8db..2a2b82d9aaa32 100644
--- a/ext/standard/tests/strings/gh18823_weak.phpt
+++ b/ext/standard/tests/strings/gh18823_weak.phpt
@@ -27,6 +27,5 @@ try {
     echo $e->getMessage(), "\n";
 }
 ?>
---EXPECTF--
-Deprecated: setlocale(): Passing null to parameter #2 ($locales) of type string is deprecated in %s on line %d
+--EXPECT--
 no
diff --git a/ext/standard/tests/strings/gh19070.phpt b/ext/standard/tests/strings/gh19070.phpt
new file mode 100644
index 0000000000000..e44696443cc97
--- /dev/null
+++ b/ext/standard/tests/strings/gh19070.phpt
@@ -0,0 +1,8 @@
+--TEST--
+GH-19070 (setlocale($type, NULL) should not be deprecated)
+--FILE--
+<?php
+var_dump(setlocale(LC_ALL, null));
+?>
+--EXPECTF--
+string(%d) "%s"