diff --git a/UPGRADING b/UPGRADING
index 94dc22eae18..64b26778a10 100644
--- a/UPGRADING
+++ b/UPGRADING
@@ -392,6 +392,9 @@ PHP 8.1 UPGRADE NOTES
     instead (for locale-independent parsing) or IntlDateFormatter::parse() (for
     locale-dependent parsing).
     RFC: https://wiki.php.net/rfc/deprecations_php_8_1
+  . The auto_detect_line_endings ini setting has been deprecated. If necessary,
+    handle "\r" line breaks manually instead.
+    RFC: https://wiki.php.net/rfc/deprecations_php_8_1
   . The FILE_BINARY and FILE_TEXT constants are deprecated. They already had
     no effect previously.
     RFC: https://wiki.php.net/rfc/deprecations_php_8_1
diff --git a/ext/standard/file.c b/ext/standard/file.c
index 17006d51911..d54201f3e43 100644
--- a/ext/standard/file.c
+++ b/ext/standard/file.c
@@ -153,11 +153,19 @@ static void file_globals_dtor(php_file_globals *file_globals_p)
 #endif
 }
 
+static PHP_INI_MH(OnUpdateAutoDetectLineEndings)
+{
+	if (zend_ini_parse_bool(new_value)) {
+		zend_error(E_DEPRECATED, "auto_detect_line_endings is deprecated");
+	}
+	return OnUpdateBool(entry, new_value, mh_arg1, mh_arg2, mh_arg3, stage);
+}
+
 PHP_INI_BEGIN()
 	STD_PHP_INI_ENTRY("user_agent", NULL, PHP_INI_ALL, OnUpdateString, user_agent, php_file_globals, file_globals)
 	STD_PHP_INI_ENTRY("from", NULL, PHP_INI_ALL, OnUpdateString, from_address, php_file_globals, file_globals)
 	STD_PHP_INI_ENTRY("default_socket_timeout", "60", PHP_INI_ALL, OnUpdateLong, default_socket_timeout, php_file_globals, file_globals)
-	STD_PHP_INI_BOOLEAN("auto_detect_line_endings", "0", PHP_INI_ALL, OnUpdateBool, auto_detect_line_endings, php_file_globals, file_globals)
+	STD_PHP_INI_BOOLEAN("auto_detect_line_endings", "0", PHP_INI_ALL, OnUpdateAutoDetectLineEndings, auto_detect_line_endings, php_file_globals, file_globals)
 PHP_INI_END()
 
 PHP_MINIT_FUNCTION(file)
diff --git a/ext/standard/tests/file/auto_detect_line_endings_1.phpt b/ext/standard/tests/file/auto_detect_line_endings_1.phpt
index 5a4ff0a10f8..4bdbabb03b5 100644
--- a/ext/standard/tests/file/auto_detect_line_endings_1.phpt
+++ b/ext/standard/tests/file/auto_detect_line_endings_1.phpt
@@ -16,6 +16,7 @@ var_dump(fgets(STDIN));
 echo "Done\n";
 ?>
 --EXPECT--
+Deprecated: auto_detect_line_endings is deprecated in Unknown on line 0
 string(1) "1"
 string(8) "fooBar1
"
 string(8) "fooBar2
"
diff --git a/ext/standard/tests/file/auto_detect_line_endings_2.phpt b/ext/standard/tests/file/auto_detect_line_endings_2.phpt
index 3994f1ee3b8..79d51535cb0 100644
--- a/ext/standard/tests/file/auto_detect_line_endings_2.phpt
+++ b/ext/standard/tests/file/auto_detect_line_endings_2.phpt
@@ -16,7 +16,8 @@ var_dump(fgets($stdin));
 
 echo "Done\n";
 ?>
---EXPECT--
+--EXPECTF--
+Deprecated: auto_detect_line_endings is deprecated in %s on line %d
 string(2) "on"
 string(8) "fooBar1
"
 string(8) "fooBar2
"