diff --git a/CHANGELOG.md b/CHANGELOG.md
index 7133be0..6eaa03c 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,3 +1,7 @@
+## 0.13.1
+
+* Fix two checked mode bugs introduced in 0.13.0.
+
 ## 0.13.0
 
  * **BREAKING** Fix all [strong mode][] errors and warnings.
diff --git a/lib/parser.dart b/lib/parser.dart
index 12c9d21..3a48929 100644
--- a/lib/parser.dart
+++ b/lib/parser.dart
@@ -775,7 +775,7 @@
 
     var name = identifier();
 
-    var params = <VarDefinition>[];
+    var params = <TreeNode>[];
     // Any parameters?
     if (_maybeEat(TokenKind.LPAREN)) {
       var mustHaveParam = false;
diff --git a/lib/src/tree.dart b/lib/src/tree.dart
index ded846d..c187903 100644
--- a/lib/src/tree.dart
+++ b/lib/src/tree.dart
@@ -696,7 +696,7 @@
 class MixinRulesetDirective extends MixinDefinition {
   final List<TreeNode> rulesets;
 
-  MixinRulesetDirective(String name, List<VarDefinition> args,
+  MixinRulesetDirective(String name, List<TreeNode> args,
       bool varArgs, this.rulesets, SourceSpan span)
       : super(name, args, varArgs, span);
 
diff --git a/pubspec.yaml b/pubspec.yaml
index 06690f5..10cb940 100644
--- a/pubspec.yaml
+++ b/pubspec.yaml
@@ -1,5 +1,5 @@
 name: csslib
-version: 0.13.0
+version: 0.13.1
 author: Dart Team <misc@dartlang.org>
 description: A library for parsing CSS.
 homepage: https://github.com/dart-lang/csslib