diff --git a/src/Markdig/Extensions/AutoIdentifiers/AutoIdentifierExtension.cs b/src/Markdig/Extensions/AutoIdentifiers/AutoIdentifierExtension.cs
index dfbf73ecf..00e81bbd9 100644
--- a/src/Markdig/Extensions/AutoIdentifiers/AutoIdentifierExtension.cs
+++ b/src/Markdig/Extensions/AutoIdentifiers/AutoIdentifierExtension.cs
@@ -2,8 +2,6 @@
 // This file is licensed under the BSD-Clause 2 license.
 // See the license.txt file in the project root for more information.
 
-using System.IO;
-
 using Markdig.Helpers;
 using Markdig.Parsers;
 using Markdig.Renderers;