diff --git a/CHANGELOG.md b/CHANGELOG.md
index 12dec49..8084be6 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,3 +1,5 @@
+## 1.15.0-nullsafety.6-dev
+
 ## 1.15.0-nullsafety.5
 
 * Fix typo in extension method `expandIndexed`.
diff --git a/README.md b/README.md
index 6c22c30..e7bd21d 100644
--- a/README.md
+++ b/README.md
@@ -16,14 +16,14 @@
 if they contain exactly the same objects as elements.
 
 The `Equality` interface provides a way to define such an equality. In this
-case, for example, `const SetEquality(const IdentityEquality())` is an equality
+case, for example, `const SetEquality(IdentityEquality())` is an equality
 that considers two sets equal exactly if they contain identical elements.
 
 Equalities are provided for `Iterable`s, `List`s, `Set`s, and `Map`s, as well as
 combinations of these, such as:
 
 ```dart
-const MapEquality(const IdentityEquality(), const ListEquality());
+const MapEquality(IdentityEquality(), ListEquality());
 ```
 
 This equality considers maps equal if they have identical keys, and the
diff --git a/pubspec.yaml b/pubspec.yaml
index 375dd91..cb0b165 100644
--- a/pubspec.yaml
+++ b/pubspec.yaml
@@ -1,5 +1,5 @@
 name: collection
-version: 1.15.0-nullsafety.5
+version: 1.15.0-nullsafety.6-dev
 
 description: Collections and utilities functions and classes related to collections.
 homepage: https://github.com/dart-lang/collection