diff --git a/tests/lean/run/heapSort.lean b/tests/lean/run/heapSort.lean
index cfd20065dc7c..7bfcdd27ca1c 100644
--- a/tests/lean/run/heapSort.lean
+++ b/tests/lean/run/heapSort.lean
@@ -176,15 +176,18 @@ def Array.toBinaryHeap (lt : α → α → Bool) (a : Array α) : BinaryHeap α
 attribute [simp] Array.heapSort.loop
 
 /--
-info: Array.heapSort.loop.eq_1.{u_1} {α : Type u_1} (gt : α → α → Bool) (a : BinaryHeap α gt) (out : Array α) :
-  Array.heapSort.loop gt a out =
+info: Array.heapSort.loop.eq_1 fun a b =>
+  decide
+    (a <
+      b) : ∀ (a : BinaryHeap Nat fun y x => decide (x < y)) (out : Array Nat),
+  Array.heapSort.loop (fun a b => decide (a < b)) a out =
     match e : a.max with
     | none => out
     | some x =>
       let_fun this := ⋯;
-      Array.heapSort.loop gt a.popMax (out.push x)
+      Array.heapSort.loop (fun a b => decide (a < b)) a.popMax (out.push x)
 -/
 #guard_msgs in
-#check Array.heapSort.loop.eq_1
+#check Array.heapSort.loop.eq_1 (fun (a b : Nat) => a < b)
 
 attribute [simp] BinaryHeap.heapifyDown