diff --git a/packages/file/lib/src/backends/chroot.dart b/packages/file/lib/src/backends/chroot.dart
index 72ce3ca..5c90a4f 100644
--- a/packages/file/lib/src/backends/chroot.dart
+++ b/packages/file/lib/src/backends/chroot.dart
@@ -4,7 +4,6 @@
 
 library file.src.backends.chroot;
 
-import 'dart:async';
 import 'dart:convert';
 import 'dart:typed_data';
 
diff --git a/packages/file/lib/src/backends/local/local_file_system.dart b/packages/file/lib/src/backends/local/local_file_system.dart
index 069c436..635998e 100644
--- a/packages/file/lib/src/backends/local/local_file_system.dart
+++ b/packages/file/lib/src/backends/local/local_file_system.dart
@@ -2,8 +2,6 @@
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
-import 'dart:async';
-
 import 'package:file/src/io.dart' as io;
 import 'package:file/file.dart';
 import 'package:path/path.dart' as p;
diff --git a/packages/file/lib/src/backends/memory/memory_directory.dart b/packages/file/lib/src/backends/memory/memory_directory.dart
index 729453d..63e40d2 100644
--- a/packages/file/lib/src/backends/memory/memory_directory.dart
+++ b/packages/file/lib/src/backends/memory/memory_directory.dart
@@ -2,8 +2,6 @@
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
-import 'dart:async';
-
 import 'package:file/file.dart';
 import 'package:file/src/common.dart' as common;
 import 'package:file/src/io.dart' as io;
diff --git a/packages/file/lib/src/backends/memory/memory_file_system.dart b/packages/file/lib/src/backends/memory/memory_file_system.dart
index 9bb82db..adb5e0a 100644
--- a/packages/file/lib/src/backends/memory/memory_file_system.dart
+++ b/packages/file/lib/src/backends/memory/memory_file_system.dart
@@ -2,8 +2,6 @@
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
-import 'dart:async';
-
 import 'package:file/file.dart';
 import 'package:file/src/io.dart' as io;
 import 'package:path/path.dart' as p;
diff --git a/packages/file/lib/src/backends/memory/memory_file_system_entity.dart b/packages/file/lib/src/backends/memory/memory_file_system_entity.dart
index d473dab..cdf64e3 100644
--- a/packages/file/lib/src/backends/memory/memory_file_system_entity.dart
+++ b/packages/file/lib/src/backends/memory/memory_file_system_entity.dart
@@ -2,8 +2,6 @@
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
-import 'dart:async';
-
 import 'package:file/file.dart';
 import 'package:file/src/common.dart' as common;
 import 'package:file/src/io.dart' as io;
diff --git a/packages/file/lib/src/backends/memory/memory_link.dart b/packages/file/lib/src/backends/memory/memory_link.dart
index b22e2fd..31c084a 100644
--- a/packages/file/lib/src/backends/memory/memory_link.dart
+++ b/packages/file/lib/src/backends/memory/memory_link.dart
@@ -2,8 +2,6 @@
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
-import 'dart:async';
-
 import 'package:file/file.dart';
 import 'package:file/src/common.dart' as common;
 import 'package:file/src/io.dart' as io;
diff --git a/packages/file/lib/src/forwarding/forwarding_directory.dart b/packages/file/lib/src/forwarding/forwarding_directory.dart
index c14d957..640f936 100644
--- a/packages/file/lib/src/forwarding/forwarding_directory.dart
+++ b/packages/file/lib/src/forwarding/forwarding_directory.dart
@@ -2,8 +2,6 @@
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
-import 'dart:async';
-
 import 'package:file/src/io.dart' as io;
 import 'package:file/file.dart';
 
diff --git a/packages/file/lib/src/forwarding/forwarding_file.dart b/packages/file/lib/src/forwarding/forwarding_file.dart
index a5fde1b..3a8c795 100644
--- a/packages/file/lib/src/forwarding/forwarding_file.dart
+++ b/packages/file/lib/src/forwarding/forwarding_file.dart
@@ -2,7 +2,6 @@
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
-import 'dart:async';
 import 'dart:convert';
 import 'dart:typed_data';
 
diff --git a/packages/file/lib/src/forwarding/forwarding_file_system.dart b/packages/file/lib/src/forwarding/forwarding_file_system.dart
index 6d027cf..d864db9 100644
--- a/packages/file/lib/src/forwarding/forwarding_file_system.dart
+++ b/packages/file/lib/src/forwarding/forwarding_file_system.dart
@@ -2,8 +2,6 @@
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
-import 'dart:async';
-
 import 'package:file/src/io.dart' as io;
 import 'package:file/file.dart';
 import 'package:meta/meta.dart';
diff --git a/packages/file/lib/src/forwarding/forwarding_file_system_entity.dart b/packages/file/lib/src/forwarding/forwarding_file_system_entity.dart
index 75804a9..3c41b39 100644
--- a/packages/file/lib/src/forwarding/forwarding_file_system_entity.dart
+++ b/packages/file/lib/src/forwarding/forwarding_file_system_entity.dart
@@ -2,8 +2,6 @@
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
-import 'dart:async';
-
 import 'package:file/src/io.dart' as io;
 import 'package:file/file.dart';
 import 'package:meta/meta.dart';
diff --git a/packages/file/lib/src/forwarding/forwarding_link.dart b/packages/file/lib/src/forwarding/forwarding_link.dart
index 6dd0403..bf3ba3b 100644
--- a/packages/file/lib/src/forwarding/forwarding_link.dart
+++ b/packages/file/lib/src/forwarding/forwarding_link.dart
@@ -2,8 +2,6 @@
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
-import 'dart:async';
-
 import 'package:file/src/io.dart' as io;
 import 'package:file/file.dart';
 
diff --git a/packages/file/lib/src/interface/directory.dart b/packages/file/lib/src/interface/directory.dart
index 4162d15..e62ad8c 100644
--- a/packages/file/lib/src/interface/directory.dart
+++ b/packages/file/lib/src/interface/directory.dart
@@ -2,8 +2,6 @@
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
-import 'dart:async';
-
 import '../io.dart' as io;
 
 import 'file.dart';
diff --git a/packages/file/lib/src/interface/file.dart b/packages/file/lib/src/interface/file.dart
index ad50475..d4267e4 100644
--- a/packages/file/lib/src/interface/file.dart
+++ b/packages/file/lib/src/interface/file.dart
@@ -2,7 +2,6 @@
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
-import 'dart:async';
 import 'dart:convert';
 
 import '../io.dart' as io;
diff --git a/packages/file/lib/src/interface/file_system.dart b/packages/file/lib/src/interface/file_system.dart
index b0cc9fd..79ef6b8 100644
--- a/packages/file/lib/src/interface/file_system.dart
+++ b/packages/file/lib/src/interface/file_system.dart
@@ -2,8 +2,6 @@
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
-import 'dart:async';
-
 import 'package:meta/meta.dart';
 import 'package:path/path.dart' as p;
 
diff --git a/packages/file/lib/src/interface/file_system_entity.dart b/packages/file/lib/src/interface/file_system_entity.dart
index 71cb667..a377397 100644
--- a/packages/file/lib/src/interface/file_system_entity.dart
+++ b/packages/file/lib/src/interface/file_system_entity.dart
@@ -2,8 +2,6 @@
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
-import 'dart:async';
-
 import '../io.dart' as io;
 
 import 'directory.dart';
diff --git a/packages/file/lib/src/interface/link.dart b/packages/file/lib/src/interface/link.dart
index 433b560..27874b3 100644
--- a/packages/file/lib/src/interface/link.dart
+++ b/packages/file/lib/src/interface/link.dart
@@ -2,8 +2,6 @@
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
-import 'dart:async';
-
 import '../io.dart' as io;
 
 import 'file_system_entity.dart';