diff --git a/CHANGELOG.md b/CHANGELOG.md
index e99669f..088e838 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,4 +1,6 @@
-## 1.15.0-nullsafety.4-dev
+## 1.15.0-nullsafety.4
+
+* Allow prerelease versions of the `2.12.x` sdk.
 
 * Remove the unusable setter `UnionSetController.set=`. This was mistakenly
   added to the public API but could never be called.
diff --git a/pubspec.yaml b/pubspec.yaml
index b94841d..8a0da72 100644
--- a/pubspec.yaml
+++ b/pubspec.yaml
@@ -1,11 +1,11 @@
 name: collection
-version: 1.15.0-nullsafety.4-dev
+version: 1.15.0-nullsafety.4
 
 description: Collections and utilities functions and classes related to collections.
 homepage: https://www.github.com/dart-lang/collection
 
 environment:
-  sdk: '>=2.10.0-78 <2.11.0'
+  sdk: '>=2.10.0-78 <2.12.0'
 
 dev_dependencies:
   pedantic: ^1.9.0