diff --git a/.travis.yml b/.travis.yml
index 7e4339b597..ba716bdcb8 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -2,7 +2,7 @@ language: dart
 sudo: false
 dart:
   - stable
-  - "dev/raw/latest"
+  - "dev/raw/2.9.0-5.0.dev"
 env:
   - DARTDOC_BOT=main
   - DARTDOC_BOT=flutter
@@ -18,7 +18,7 @@ matrix:
   include:
   - env: DARTDOC_BOT=main
     os: osx
-    dart: "dev/raw/latest"
+    dart: "dev/raw/2.9.0-5.0.dev"
 
 install:
 - ./tool/install_travis.sh
diff --git a/appveyor.yml b/appveyor.yml
index e58a645699..2f19250fd0 100644
--- a/appveyor.yml
+++ b/appveyor.yml
@@ -7,7 +7,7 @@ branches:
     - master
 
 install:
-  - ps: wget https://storage.googleapis.com/dart-archive/channels/dev/release/latest/sdk/dartsdk-windows-x64-release.zip -OutFile dart-sdk.zip
+  - ps: wget https://storage.googleapis.com/dart-archive/channels/dev/release/2.9.0-5.0.dev/sdk/dartsdk-windows-x64-release.zip -OutFile dart-sdk.zip
   - cmd: echo "Unzipping dart-sdk..."
   - cmd: 7z x dart-sdk.zip -o"C:\tools" -y > nul
   - cmd: del dart-sdk.zip
diff --git a/test/model_special_cases_test.dart b/test/model_special_cases_test.dart
index 2d11f00712..9cabd67ba7 100644
--- a/test/model_special_cases_test.dart
+++ b/test/model_special_cases_test.dart
@@ -14,10 +14,14 @@ import 'package:dartdoc/dartdoc.dart';
 import 'package:dartdoc/src/model/model.dart';
 import 'package:dartdoc/src/special_elements.dart';
 import 'package:dartdoc/src/warnings.dart';
+import 'package:pub_semver/pub_semver.dart';
 import 'package:test/test.dart';
 
 import 'src/utils.dart' as utils;
 
+final String _platformVersionString = Platform.version.split(' ').first;
+final Version _platformVersion = Version.parse(_platformVersionString);
+
 void main() {
   var sdkDir = defaultSdkDir;
 
@@ -26,11 +30,19 @@ void main() {
     exit(1);
   }
 
+  // This doesn't have the `max` because NNBD is supposed to work after this
+  // version, and if the `max` is placed here we'll silently pass 2.10 stable
+  // if we haven't figured out how to switch on NNBD outside of `dev` builds
+  // as specified in #2148.
+  final _nnbdExperimentAllowed =
+      VersionRange(min: Version.parse('2.9.0'), includeMin: true);
+
   // Experimental features not yet enabled by default.  Move tests out of this block
   // when the feature is enabled by default.
   group('Experiments', () {
     Library lateFinalWithoutInitializer, nnbdClassMemberDeclarations;
     Class b;
+
     setUpAll(() async {
       lateFinalWithoutInitializer = (await utils.testPackageGraphExperiments)
           .libraries
@@ -120,7 +132,9 @@ void main() {
       expect(initializeMe.isLate, isTrue);
       expect(initializeMe.features, contains('late'));
     });
-  }, skip: 'dart-lang/dartdoc#2148');
+  },
+      skip: (!_nnbdExperimentAllowed.allows(_platformVersion) &&
+          !_platformVersionString.contains('edge')));
 
   group('HTML Injection when allowed', () {
     Class htmlInjection;
diff --git a/testing/test_package_experiments/pubspec.yaml b/testing/test_package_experiments/pubspec.yaml
index 35afe7fbbf..bda7ea23fb 100644
--- a/testing/test_package_experiments/pubspec.yaml
+++ b/testing/test_package_experiments/pubspec.yaml
@@ -1,3 +1,4 @@
 name: test_package_experiments
 version: 0.0.1
+sdk: '>=2.9.0 <2.10.0'
 description: Experimental flags are tested here.
diff --git a/tool/grind.dart b/tool/grind.dart
index 8014b1239c..db7068b5e6 100644
--- a/tool/grind.dart
+++ b/tool/grind.dart
@@ -117,6 +117,9 @@ Directory get flutterDir => _flutterDir ??= createTempSync('flutter');
 Directory get testPackage =>
     Directory(path.joinAll(['testing', 'test_package']));
 
+Directory get testPackageExperiments =>
+    Directory(path.joinAll(['testing', 'test_package_experiments']));
+
 Directory get pluginPackage =>
     Directory(path.joinAll(['testing', 'test_package_flutter_plugin']));
 
@@ -125,6 +128,11 @@ Directory _testPackageDocsDir;
 Directory get testPackageDocsDir =>
     _testPackageDocsDir ??= createTempSync('test_package');
 
+Directory _testPackageExperimentsDocsDir;
+Directory get testPackageExperimentsDocsDir =>
+    _testPackageExperimentsDocsDir ??=
+        createTempSync('test_package_experiments');
+
 Directory _pluginPackageDocsDir;
 
 Directory get pluginPackageDocsDir =>
@@ -497,15 +505,14 @@ Future<List<Map>> _buildSdkDocs(String sdkDocsPath, Future<String> futureCwd,
       workingDirectory: cwd);
 }
 
-Future<List<Map>> _buildTestPackageDocs(
-    String outputDir, Future<String> futureCwd,
-    [String label]) async {
-  label ??= '';
+Future<List<Map>> _buildTestPackageDocs(String outputDir, String cwd,
+    {List<String> params, String label = '', String testPackagePath}) async {
   if (label != '') label = '-$label';
+  testPackagePath ??= testPackage.absolute.path;
+  params ??= [];
   var launcher = SubprocessLauncher('build-test-package-docs$label');
   Future testPackagePubGet = launcher.runStreamed(sdkBin('pub'), ['get'],
-      workingDirectory: testPackage.absolute.path);
-  var cwd = await futureCwd;
+      workingDirectory: testPackagePath);
   Future dartdocPubGet =
       launcher.runStreamed(sdkBin('pub'), ['get'], workingDirectory: cwd);
   await Future.wait([testPackagePubGet, dartdocPubGet]);
@@ -522,16 +529,33 @@ Future<List<Map>> _buildTestPackageDocs(
         '--json',
         '--link-to-remote',
         '--pretty-index-json',
+        ...params,
         ...extraDartdocParameters,
       ],
-      workingDirectory: testPackage.absolute.path);
+      workingDirectory: testPackagePath);
+}
+
+@Task('Build generated test package docs from the experiment test package')
+@Depends(clean)
+Future<void> buildTestExperimentsPackageDocs() async {
+  await _buildTestPackageDocs(
+      testPackageExperimentsDocsDir.absolute.path, Directory.current.path,
+      testPackagePath: testPackageExperiments.absolute.path,
+      params: ['--enable-experiment', 'non-nullable', '--no-link-to-remote']);
+}
+
+@Task('Serve experimental test package on port 8003.')
+@Depends(buildTestExperimentsPackageDocs)
+Future<void> serveTestExperimentsPackageDocs() async {
+  await _serveDocsFrom(testPackageExperimentsDocsDir.absolute.path, 8003,
+      'test-package-docs-experiments');
 }
 
 @Task('Build generated test package docs (with inherited docs and source code)')
 @Depends(clean)
 Future<void> buildTestPackageDocs() async {
   await _buildTestPackageDocs(
-      testPackageDocsDir.absolute.path, Future.value(Directory.current.path));
+      testPackageDocsDir.absolute.path, Directory.current.path);
 }
 
 @Task('Serve test package docs locally with dhttpd on port 8002')
@@ -549,11 +573,16 @@ Future<void> serveTestPackageDocs() async {
   ]);
 }
 
+bool _serveReady = false;
+
 Future<void> _serveDocsFrom(String servePath, int port, String context) async {
   log('launching dhttpd on port $port for $context');
   var launcher = SubprocessLauncher(context);
-  await launcher.runStreamed(sdkBin('pub'), ['get']);
-  await launcher.runStreamed(sdkBin('pub'), ['global', 'activate', 'dhttpd']);
+  if (!_serveReady) {
+    await launcher.runStreamed(sdkBin('pub'), ['get']);
+    await launcher.runStreamed(sdkBin('pub'), ['global', 'activate', 'dhttpd']);
+    _serveReady = true;
+  }
   await launcher.runStreamed(
       sdkBin('pub'), ['run', 'dhttpd', '--port', '$port', '--path', servePath]);
 }