diff --git a/lib/transformer.dart b/lib/transformer.dart
index 21555002..adcc9117 100644
--- a/lib/transformer.dart
+++ b/lib/transformer.dart
@@ -23,8 +23,10 @@ class ChromeTransformer extends Transformer {
 
   ChromeTransformer.asPlugin();
 
-  Future<bool> isPrimary(Asset input) {
-    return new Future.value(input.id.extension == '.html');
+  // TODO: Remove the [assetOrId] hack.
+  Future<bool> isPrimary(assetOrId) {
+    AssetId id = assetOrId is Asset ? assetOrId.id : assetOrId;
+    return new Future.value(id.extension == '.html');
   }
 
   Future apply(Transform transform) {
diff --git a/pubspec.yaml b/pubspec.yaml
index ae0e0435..981dba34 100644
--- a/pubspec.yaml
+++ b/pubspec.yaml
@@ -1,5 +1,5 @@
 name: chrome
-version: 0.5.5-dev
+version: 0.5.5
 environment:
   sdk: ">=1.0.0 <2.0.0"
 authors: