diff --git a/src/Features/LanguageServer/Protocol/LanguageInfoProvider.cs b/src/Features/LanguageServer/Protocol/LanguageInfoProvider.cs
index 6564c452ae721..c63e1fb1b9e5b 100644
--- a/src/Features/LanguageServer/Protocol/LanguageInfoProvider.cs
+++ b/src/Features/LanguageServer/Protocol/LanguageInfoProvider.cs
@@ -37,6 +37,7 @@ internal class LanguageInfoProvider : ILanguageInfoProvider
             { ".cjs", s_typeScriptLanguageInformation },
             { ".mjs", s_typeScriptLanguageInformation },
             { ".cts", s_typeScriptLanguageInformation },
+            { ".mts", s_typeScriptLanguageInformation },
         };
 
         public LanguageInformation GetLanguageInformation(string documentPath, string? lspLanguageId)