diff --git a/pubspec.yaml b/pubspec.yaml
index 4c3c8f0..fb979a0 100644
--- a/pubspec.yaml
+++ b/pubspec.yaml
@@ -1,9 +1,9 @@
 name: collection
-version: 0.9.1-dev+1
+version: 0.9.2-dev
 author: Dart Team <misc@dartlang.org>
 description: Collections and utilities functions and classes related to collections.
 homepage: http://www.dartlang.org
-dev_dependencies:
-  unittest: ">=0.9.0 <0.10.0"
 environment:
-  sdk: ">=1.0.0 <2.0.0"
+  sdk: '>=1.0.0 <2.0.0'
+dev_dependencies:
+  unittest: '>=0.9.0 <0.11.0'
diff --git a/test/priority_queue_test.dart b/test/priority_queue_test.dart
index 1040e1a..703ab72 100644
--- a/test/priority_queue_test.dart
+++ b/test/priority_queue_test.dart
@@ -4,7 +4,6 @@
 
 /// Tests priority queue implementations utilities.
 
-import "dart:collection";
 import "package:collection/priority_queue.dart";
 import "package:unittest/unittest.dart";