diff --git a/.travis.yml b/.travis.yml
index bf594a88..f23ac82a 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -3,25 +3,20 @@
 # Set the language to Ruby so that we can run sass-spec tests.
 language: ruby
 
-# TODO(nweiz): We're currently locked to Dart 2.0.0 and 2.0.0-dev.5.0 because
-# 2.0.0-dev.6.0 removes the --preview-dart-2 flag, which we use because it's
-# faster than Dart 2 mode (at least in 2.0.0). Re-enable tracking the latest
-# stable and dev versions once a stable release is out where Dart 2 mode is
-# verified to be faster than Dart 1 mode was in Dart 2.1.0.
-
 env:
   global:
   - DART_CHANNEL=stable
-  - DART_VERSION=2.0.0
+  - DART_VERSION=latest
   matrix:
   # Language specs, defined in sass/sass-spec
   - TASK=specs
-  - TASK=specs DART_CHANNEL=dev DART_VERSION=2.1.0-dev.5.0
+  - TASK=specs DART_CHANNEL=dev
   - TASK=specs ASYNC=true
 
   # Unit tests, defined in test/.
   - TASK=tests
-  - TASK=tests DART_CHANNEL=dev DART_VERSION=2.1.0-dev.5.0
+  - TASK=tests DART_VERSION=2.0.0
+  - TASK=tests DART_CHANNEL=dev
   - TASK=tests NODE_VERSION=stable
 
   # Keep these up-to-date with the latest LTA Node releases. They next need to be
diff --git a/package/chocolatey/sass.bat b/package/chocolatey/sass.bat
index cd73546a..954937b0 100644
--- a/package/chocolatey/sass.bat
+++ b/package/chocolatey/sass.bat
@@ -5,4 +5,4 @@ REM https://opensource.org/licenses/MIT.
 
 set SCRIPTPATH=%~dp0
 set arguments=%*
-dart.exe --no-preview-dart-2 "-Dversion=SASS_VERSION" "%SCRIPTPATH%\sass.dart.snapshot" %arguments%
+dart.exe "-Dversion=SASS_VERSION" "%SCRIPTPATH%\sass.dart.snapshot" %arguments%
diff --git a/package/dart-sass.bat b/package/dart-sass.bat
index cf96390e..4c4c00c3 100644
--- a/package/dart-sass.bat
+++ b/package/dart-sass.bat
@@ -11,4 +11,4 @@ echo "WARNING: The dart-sass executable is deprecated, use sass instead."
 
 set SCRIPTPATH=%~dp0
 set arguments=%*
-"%SCRIPTPATH%\src\dart.exe" --no-preview-dart-2 "-Dversion=SASS_VERSION" "%SCRIPTPATH%\src\sass.dart.snapshot" %arguments%
+"%SCRIPTPATH%\src\dart.exe" "-Dversion=SASS_VERSION" "%SCRIPTPATH%\src\sass.dart.snapshot" %arguments%
diff --git a/package/dart-sass.sh b/package/dart-sass.sh
index e84bc21c..fb07d8b2 100644
--- a/package/dart-sass.sh
+++ b/package/dart-sass.sh
@@ -22,4 +22,4 @@ fi
 
 # Unlike $0, $BASH_SOURCE points to the absolute path of this file.
 path=`dirname "$(follow_links "$BASH_SOURCE")"`
-exec "$path/src/dart" --no-preview-dart-2 "-Dversion=SASS_VERSION" "$path/src/sass.dart.snapshot" "$@"
+exec "$path/src/dart" "-Dversion=SASS_VERSION" "$path/src/sass.dart.snapshot" "$@"
diff --git a/package/sass.bat b/package/sass.bat
index de094955..6f8ba025 100644
--- a/package/sass.bat
+++ b/package/sass.bat
@@ -9,4 +9,4 @@ REM grinder package`.
 
 set SCRIPTPATH=%~dp0
 set arguments=%*
-"%SCRIPTPATH%\src\dart.exe" --no-preview-dart-2 "-Dversion=SASS_VERSION" "%SCRIPTPATH%\src\sass.dart.snapshot" %arguments%
+"%SCRIPTPATH%\src\dart.exe" "-Dversion=SASS_VERSION" "%SCRIPTPATH%\src\sass.dart.snapshot" %arguments%
diff --git a/package/sass.sh b/package/sass.sh
index 98dab825..4a2812e8 100644
--- a/package/sass.sh
+++ b/package/sass.sh
@@ -18,4 +18,4 @@ follow_links() {
 
 # Unlike $0, $BASH_SOURCE points to the absolute path of this file.
 path=`dirname "$(follow_links "$0")"`
-exec "$path/src/dart" --no-preview-dart-2 "-Dversion=SASS_VERSION" "$path/src/sass.dart.snapshot" "$@"
+exec "$path/src/dart" "-Dversion=SASS_VERSION" "$path/src/sass.dart.snapshot" "$@"
diff --git a/test/cli/dart_test.dart b/test/cli/dart_test.dart
index f28f7ece..08cfa97b 100644
--- a/test/cli/dart_test.dart
+++ b/test/cli/dart_test.dart
@@ -51,7 +51,7 @@ Future<TestProcess> runSass(Iterable<String> arguments,
       (path) => new File(path).existsSync(),
       orElse: () => p.absolute("bin/sass.dart"));
 
-  var args = ["--no-preview-dart-2", "--checked"];
+  var args = ["--enable-asserts"];
 
   // Work around dart-lang/sdk#33622.
   if (Platform.isWindows) args.add("--packages=${p.absolute('.packages')}");
diff --git a/tool/grind/benchmark.dart b/tool/grind/benchmark.dart
index 411fb061..73df5114 100644
--- a/tool/grind/benchmark.dart
+++ b/tool/grind/benchmark.dart
@@ -90,8 +90,7 @@ Future _writeNTimes(String path, String text, num times,
 }
 
 @Task('Run benchmarks for Sass compilation speed.')
-@Depends(benchmarkGenerate, snapshot, releaseAppSnapshot, snapshotDart2,
-    releaseDart2AppSnapshot, npmReleasePackage)
+@Depends(benchmarkGenerate, snapshot, releaseAppSnapshot, npmReleasePackage)
 benchmark() async {
   var libsass = await cloneOrPull('https://github.com/sass/libsass');
   var sassc = await cloneOrPull('https://github.com/sass/sassc');
@@ -184,35 +183,21 @@ I ran five instances of each configuration and recorded the fastest time.
     var sasscTime = await _benchmark(p.join(sassc, 'bin', 'sassc'), [path]);
     buffer.writeln("* sassc: ${_formatTime(sasscTime)}");
 
-    var scriptSnapshotTime = await _benchmark(Platform.executable,
-        ['--no-preview-dart-2', p.join('build', 'sass.dart.snapshot'), path]);
-    buffer.writeln("* Dart Sass from a Dart 1 script snapshot: "
+    var scriptSnapshotTime = await _benchmark(Platform.executable, [
+      '--no-enable-asserts',
+      p.join('build', 'sass.dart.snapshot'),
+      path
+    ]);
+    buffer.writeln("* Dart Sass from a script snapshot: "
         "${_formatTime(scriptSnapshotTime)}");
 
     var appSnapshotTime = await _benchmark(Platform.executable, [
-      '--no-preview-dart-2',
-      '--no-checked',
+      '--no-enable-asserts',
       p.join('build', 'sass.dart.app.snapshot'),
       path
     ]);
-    buffer.writeln(
-        "* Dart Sass from a Dart 1 app snapshot: ${_formatTime(appSnapshotTime)}");
-
-    var dart2ScriptSnapshotTime = await _benchmark(Platform.executable, [
-      '--no-enable-asserts',
-      p.join('build', 'sass.dart.dart2.snapshot'),
-      path
-    ]);
-    buffer.writeln("* Dart Sass from a Dart 2 script snapshot: "
-        "${_formatTime(dart2ScriptSnapshotTime)}");
-
-    var dart2AppSnapshotTime = await _benchmark(Platform.executable, [
-      '--no-enable-asserts',
-      p.join('build', 'sass.dart.app.dart2.snapshot'),
-      path
-    ]);
-    buffer.writeln("* Dart Sass from a Dart 2 app snapshot: "
-        "${_formatTime(dart2AppSnapshotTime)}");
+    buffer.writeln("* Dart Sass from an app snapshot: "
+        "${_formatTime(appSnapshotTime)}");
 
     var nodeTime =
         await _benchmark("node", [p.join('build', 'npm', 'sass.js'), path]);
@@ -227,15 +212,10 @@ I ran five instances of each configuration and recorded the fastest time.
         'approximately:');
     buffer.writeln();
     buffer.writeln('* ${_compare(appSnapshotTime, sasscTime)} libsass');
-    buffer
-        .writeln('* ${_compare(appSnapshotTime, dart2AppSnapshotTime)} Dart 2');
     buffer
         .writeln('* ${_compare(appSnapshotTime, nodeTime)} Dart Sass on Node');
     buffer.writeln('* ${_compare(appSnapshotTime, rubyTime)} Ruby Sass');
     buffer.writeln();
-    buffer.writeln('A Dart 1 script snapshot is approximately '
-        '${_compare(scriptSnapshotTime, dart2ScriptSnapshotTime)} Dart 2.');
-    buffer.writeln();
     log('');
   }
 
diff --git a/tool/grind/standalone.dart b/tool/grind/standalone.dart
index 69d4f7e1..135b45fe 100644
--- a/tool/grind/standalone.dart
+++ b/tool/grind/standalone.dart
@@ -20,14 +20,7 @@ bool get _is64Bit => Platform.version.contains("x64");
 snapshot() {
   ensureBuild();
   Dart.run('bin/sass.dart',
-      vmArgs: ['--no-preview-dart-2', '--snapshot=build/sass.dart.snapshot']);
-}
-
-@Task('Build Dart 2 script snapshot.')
-snapshotDart2() {
-  ensureBuild();
-  Dart.run('bin/sass.dart',
-      vmArgs: ['--snapshot=build/sass.dart.dart2.snapshot']);
+      vmArgs: ['--snapshot=build/sass.dart.snapshot']);
 }
 
 @Task('Build a dev-mode Dart application snapshot.')
@@ -38,29 +31,17 @@ appSnapshot() => _appSnapshot(release: false);
 @Task('Build a release-mode Dart application snapshot.')
 releaseAppSnapshot() => _appSnapshot(release: true);
 
-@Task('Build a release-mode Dart 2 application snapshot.')
-releaseDart2AppSnapshot() => _appSnapshot(release: true, dart2: true);
-
 /// Compiles Sass to an application snapshot.
 ///
 /// If [release] is `true`, this compiles in checked mode. Otherwise, it
-/// compiles in unchecked mode. If [dart2] is `true`, this compiles in Dart 2
-/// mode. Otherwise, it compiles in Dart 1 mode.
-void _appSnapshot({@required bool release, bool dart2: false}) {
+/// compiles in unchecked mode.
+void _appSnapshot({@required bool release}) {
   var args = [
-    '--snapshot=build/sass.dart.app${dart2 ? '.dart2' : ''}.snapshot',
+    '--snapshot=build/sass.dart.app.snapshot',
     '--snapshot-kind=app-jit'
   ];
 
-  if (!dart2) args.add('--no-preview-dart-2');
-
-  if (!release) {
-    if (dart2) {
-      args.add('--enable-asserts');
-    } else {
-      args.add('--checked');
-    }
-  }
+  if (!release) args.add('--enable-asserts');
 
   ensureBuild();
   Dart.run('bin/sass.dart',