diff --git a/CHANGELOG.md b/CHANGELOG.md
index fd3bd74..2d30380 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,6 +1,7 @@
 #### 0.12.4
   * Update to JS version
     [0.7.23](https://github.com/webcomponents/webcomponentsjs/tree/v0.7.23).
+  * Update `analyzer`, `code_transformers`, and `html` version constraints.
 
 #### 0.12.3
   * Update to JS version
diff --git a/pubspec.yaml b/pubspec.yaml
index bf1bdf5..e41161b 100644
--- a/pubspec.yaml
+++ b/pubspec.yaml
@@ -10,10 +10,10 @@
   elements, by hiding DOM subtrees under shadow roots. HTML Imports let authors
   bundle code and HTML as if they were libraries.
 dependencies:
-  analyzer: '^0.27.0'
+  analyzer: '>=0.27.0 <0.30.0'
   barback: '>=0.14.2 <0.16.0'
-  code_transformers: '>=0.3.0 <0.5.0'
-  html: '^0.12.0'
+  code_transformers: '>=0.3.0 <0.6.0'
+  html: '>=0.12.0 <0.14.0'
   initialize: '^0.6.0'
   path: '^1.3.0'
 dev_dependencies:
@@ -32,6 +32,5 @@
       - test/init_web_components_test.html
 - test/pub_serve:
     $include: test/**_test{.*,}.dart
-
 environment:
   sdk: ">=1.9.0-dev.7.1 <2.0.0"