fix: tests

diff --git a/tests/elab/async_cancellation.lean b/tests/elab/async_cancellation.lean
index 3c424c9..855fbd3 100644
--- a/tests/elab/async_cancellation.lean
+++ b/tests/elab/async_cancellation.lean

@@ -1,7 +1,7 @@
 import Std.Async
 import Std.Sync
 
-open Std.Async
+open Std Async
 
 def cancellableSelector [Monad m] [MonadLift IO m] [MonadAsync AsyncTask m] (fn : Std.CancellationToken → m α) : m (Selector (Except IO.Error α)) := do
   let signal ← Std.CancellationToken.new

diff --git a/tests/elab/async_cancellation_reasons.lean b/tests/elab/async_cancellation_reasons.lean
index b8c1216..57d7edf 100644
--- a/tests/elab/async_cancellation_reasons.lean
+++ b/tests/elab/async_cancellation_reasons.lean

@@ -1,7 +1,7 @@
 import Std.Async
 import Std.Sync
 
-open Std.Async
+open Std Async
 
 -- Test basic cancellation with default reason
 def testBasicCancellationWithReason : Async Unit := do

diff --git a/tests/elab/cancellation_context.lean b/tests/elab/cancellation_context.lean
index c226e3b..ee2d12e 100644
--- a/tests/elab/cancellation_context.lean
+++ b/tests/elab/cancellation_context.lean

@@ -1,7 +1,7 @@
 import Std.Async
 import Std.Sync
 
-open Std.Async
+open Std Async
 
 /-- Test basic tree cancellation -/
 partial def testCancelTree : IO Unit := do

diff --git a/tests/elab/context_async.lean b/tests/elab/context_async.lean
index d87596d..cbd6dfb 100644
--- a/tests/elab/context_async.lean
+++ b/tests/elab/context_async.lean

@@ -1,7 +1,7 @@
 import Std.Async
 import Std.Sync
 
-open Std.Async
+open Std Async
 
 /-- Test ContextAsync cancellation check -/
 def testIsCancelled : IO Unit := do