diff --git a/src/Lean/Server/FileWorker.lean b/src/Lean/Server/FileWorker.lean
index ab75e7a9f5..659dede5ba 100644
--- a/src/Lean/Server/FileWorker.lean
+++ b/src/Lean/Server/FileWorker.lean
@@ -353,7 +353,7 @@ def setupImports (meta : DocumentMeta) (cmdlineOpts : Options) (chanOut : Std.Ch
   let opts := cmdlineOpts.mergeBy (fun _ _ fileOpt => fileOpt) fileSetupResult.fileOptions
 
   -- default to async elaboration; see also `Elab.async` docs
-  --let opts := Elab.async.setIfNotSet opts true
+  let opts := Elab.async.setIfNotSet opts true
 
   return .ok {
     mainModuleName