diff --git a/Userland/Libraries/LibWeb/MimeSniff/MimeType.h b/Userland/Libraries/LibWeb/MimeSniff/MimeType.h
index 0030d6fde5..cf8a6ae59b 100644
--- a/Userland/Libraries/LibWeb/MimeSniff/MimeType.h
+++ b/Userland/Libraries/LibWeb/MimeSniff/MimeType.h
@@ -8,6 +8,7 @@
 #pragma once
 
 #include <AK/HashMap.h>
+#include <AK/String.h>
 
 namespace Web::MimeSniff {