diff --git a/pkgs/io/.github/workflows/ci.yml b/pkgs/io/.github/workflows/ci.yml
index 3a83ef8..4c1304b 100644
--- a/pkgs/io/.github/workflows/ci.yml
+++ b/pkgs/io/.github/workflows/ci.yml
@@ -20,7 +20,7 @@
     strategy:
       fail-fast: false
       matrix:
-        sdk: [dev, 3.0.0]
+        sdk: [dev, 3.4]
     steps:
       - uses: actions/checkout@692973e3d937129bcbf40652eb9f2f61becf3332
       - uses: dart-lang/setup-dart@0a8a0fc875eb934c15d08629302413c671d3f672
@@ -47,7 +47,7 @@
       matrix:
         # Add macos-latest and/or windows-latest if relevant for this package.
         os: [ubuntu-latest]
-        sdk: [dev, 3.0.0]
+        sdk: [dev, 3.4]
     steps:
       - uses: actions/checkout@692973e3d937129bcbf40652eb9f2f61becf3332
       - uses: dart-lang/setup-dart@0a8a0fc875eb934c15d08629302413c671d3f672
diff --git a/pkgs/io/CHANGELOG.md b/pkgs/io/CHANGELOG.md
index e723cd6..62c0076 100644
--- a/pkgs/io/CHANGELOG.md
+++ b/pkgs/io/CHANGELOG.md
@@ -1,6 +1,6 @@
 ## 1.0.5-wip
 
-* Require Dart 3.0.
+* Require Dart 3.4.
 
 ## 1.0.4
 
diff --git a/pkgs/io/lib/src/shell_words.dart b/pkgs/io/lib/src/shell_words.dart
index ea48aa9..3a76ce5 100644
--- a/pkgs/io/lib/src/shell_words.dart
+++ b/pkgs/io/lib/src/shell_words.dart
@@ -124,7 +124,6 @@
       default:
         hasToken = true;
         token.writeCharCode(next);
-        break;
     }
   }
 
diff --git a/pkgs/io/pubspec.yaml b/pkgs/io/pubspec.yaml
index dc7c358..dd76841 100644
--- a/pkgs/io/pubspec.yaml
+++ b/pkgs/io/pubspec.yaml
@@ -6,7 +6,7 @@
 repository: https://github.com/dart-lang/io
 
 environment:
-  sdk: ^3.0.0
+  sdk: ^3.4.0
 
 dependencies:
   meta: ^1.3.0
@@ -14,6 +14,6 @@
   string_scanner: ^1.1.0
 
 dev_dependencies:
-  dart_flutter_team_lints: ^2.0.0
-  test: ^1.16.0
+  dart_flutter_team_lints: ^3.0.0
+  test: ^1.16.6
   test_descriptor: ^2.0.0