diff --git a/src/lake/Lake/Util/Proc.lean b/src/lake/Lake/Util/Proc.lean
index ec4dd70bc44f..f40f70d92345 100644
--- a/src/lake/Lake/Util/Proc.lean
+++ b/src/lake/Lake/Util/Proc.lean
@@ -57,6 +57,7 @@ def testProc (args : IO.Process.SpawnArgs) : BaseIO Bool :=
   EIO.catchExceptions (h := fun _ => pure false) do
     let child ← IO.Process.spawn {
       args with
+      stdin := IO.Process.Stdio.null
       stdout := IO.Process.Stdio.null
       stderr := IO.Process.Stdio.null
     }