diff --git a/src/extension.ts b/src/extension.ts
index 85f148fd..fee1b27b 100644
--- a/src/extension.ts
+++ b/src/extension.ts
@@ -188,6 +188,7 @@ async function activateServerForFolder(context: ExtensionContext, uri: Uri, fold
     documentSelector: [
       { scheme: 'file', language: 'haskell', pattern: pat },
       { scheme: 'file', language: 'literate haskell', pattern: pat },
+      { scheme: 'file', language: 'cabal', pattern: pat },
     ],
     synchronize: {
       // Synchronize the setting section 'haskell' to the server.