allow the 2.12 prerelease sdks (#41)

diff --git a/CHANGELOG.md b/CHANGELOG.md
index e03f158..308fd72 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,3 +1,7 @@
+## 1.3.0-nullsafety.4
+
+* Allow prerelease versions of the `2.12` sdk.
+
 ## 1.3.0-nullsafety.3
 
 * Allow 2.10 stable and 2.11.0 dev SDK versions.
diff --git a/pubspec.yaml b/pubspec.yaml
index a7ce1fe..551ec42 100644
--- a/pubspec.yaml
+++ b/pubspec.yaml
@@ -1,5 +1,5 @@
 name: typed_data
-version: 1.3.0-nullsafety.3
+version: 1.3.0-nullsafety.4
 
 description: >-
   Utility functions and classes related to the dart:typed_data library.
@@ -7,7 +7,7 @@
 
 environment:
   # This must remain a tight constraint until nnbd is stable
-  sdk: '>=2.10.0-0 <2.11.0'
+  sdk: '>=2.10.0-0 <2.12.0'
 
 dependencies:
   collection: '>=1.15.0-nullsafety <1.15.0'