diff --git a/libraries/joomla/filesystem/file.php b/libraries/joomla/filesystem/file.php
index 01e728bbb4fb4..8632b8c852550 100644
--- a/libraries/joomla/filesystem/file.php
+++ b/libraries/joomla/filesystem/file.php
@@ -65,7 +65,10 @@ public static function makeSafe($file)
 		// Remove any trailing dots, as those aren't ever valid file names.
 		$file = rtrim($file, '.');
 
-		$regex = array('#(\.){2,}#', '#[^A-Za-z0-9\.\_\- ]#', '#^\.#');
+		// Allow uploading UTF-8 filenames in Windows starting from PHP 7.1 and other OS
+		$unicode = strtoupper(substr(PHP_OS, 0, 3)) !== 'WIN' || version_compare(PHP_VERSION, '7.1', '>=') ? 'u' : '';
+
+		$regex = array('#(\.){2,}#', '#[^\w\.\- ]#' . $unicode, '#^\.#');
 
 		return trim(preg_replace($regex, '', $file));
 	}
diff --git a/libraries/joomla/filesystem/folder.php b/libraries/joomla/filesystem/folder.php
index 178f0eb4d58e0..16f77768e4c7d 100644
--- a/libraries/joomla/filesystem/folder.php
+++ b/libraries/joomla/filesystem/folder.php
@@ -715,7 +715,10 @@ public static function listFolderTree($path, $filter, $maxLevel = 3, $level = 0,
 	 */
 	public static function makeSafe($path)
 	{
-		$regex = array('#[^A-Za-z0-9_\\\/\(\)\[\]\{\}\#\$\^\+\.\'~`!@&=;,-]#');
+		// Allow uploading UTF-8 filenames in Windows starting from PHP 7.1 and other OS
+		$unicode = strtoupper(substr(PHP_OS, 0, 3)) !== 'WIN' || version_compare(PHP_VERSION, '7.1', '>=') ? 'u' : '';
+
+		$regex = array('#[^\w\\\/\(\)\[\]\{\}\#\$\^\+\.\'~`!@&=;,-]#' . $unicode);
 
 		return preg_replace($regex, '', $path);
 	}