diff --git a/packages/go_router/CHANGELOG.md b/packages/go_router/CHANGELOG.md
index fe4b38e0636..b62f174d7fb 100644
--- a/packages/go_router/CHANGELOG.md
+++ b/packages/go_router/CHANGELOG.md
@@ -1,3 +1,8 @@
+## 12.1.2
+
+* Fixes an incorrect use of `extends` for Dart 3 compatibility.
+* Updates minimum supported SDK version to Flutter 3.10/Dart 3.0.
+
 ## 12.1.1
 
 - Retains query parameters during refresh and first redirect.
@@ -75,7 +80,7 @@
 
 ## 10.1.1
 
-- Fixes mapping from `Page` to `RouteMatch`s. 
+- Fixes mapping from `Page` to `RouteMatch`s.
 - Updates minimum supported SDK version to Flutter 3.7/Dart 2.19.
 
 ## 10.1.0
diff --git a/packages/go_router/example/pubspec.yaml b/packages/go_router/example/pubspec.yaml
index 3ff5906016d..226ef8cddbf 100644
--- a/packages/go_router/example/pubspec.yaml
+++ b/packages/go_router/example/pubspec.yaml
@@ -4,8 +4,8 @@ version: 3.0.1
 publish_to: none
 
 environment:
-  sdk: ">=2.19.0 <4.0.0"
-  flutter: ">=3.7.0"
+  sdk: ">=3.0.0 <4.0.0"
+  flutter: ">=3.10.0"
 
 dependencies:
   adaptive_navigation: ^0.0.4
diff --git a/packages/go_router/lib/src/delegate.dart b/packages/go_router/lib/src/delegate.dart
index bcd737a6536..756eba28d79 100644
--- a/packages/go_router/lib/src/delegate.dart
+++ b/packages/go_router/lib/src/delegate.dart
@@ -247,7 +247,7 @@ class GoRouterDelegate extends RouterDelegate<RouteMatchList>
 /// The iterator starts with the navigator that hosts the top-most route. This
 /// navigator may not be the inner-most navigator if the top-most route is a
 /// pageless route, such as a dialog or bottom sheet.
-class _NavigatorStateIterator extends Iterator<NavigatorState> {
+class _NavigatorStateIterator implements Iterator<NavigatorState> {
   _NavigatorStateIterator(this.matchList, this.root)
       : index = matchList.matches.length - 1;
 
diff --git a/packages/go_router/pubspec.yaml b/packages/go_router/pubspec.yaml
index 7247f2a3cdf..b0360ff6011 100644
--- a/packages/go_router/pubspec.yaml
+++ b/packages/go_router/pubspec.yaml
@@ -1,13 +1,13 @@
 name: go_router
 description: A declarative router for Flutter based on Navigation 2 supporting
   deep linking, data-driven routes and more
-version: 12.1.1
+version: 12.1.2
 repository: https://github.com/flutter/packages/tree/main/packages/go_router
 issue_tracker: https://github.com/flutter/flutter/issues?q=is%3Aissue+is%3Aopen+label%3A%22p%3A+go_router%22
 
 environment:
-  sdk: ">=2.19.0 <4.0.0"
-  flutter: ">=3.7.0"
+  sdk: ">=3.0.0 <4.0.0"
+  flutter: ">=3.10.0"
 
 dependencies:
   collection: ^1.15.0