diff --git a/angel_serialize_generator/CHANGELOG.md b/angel_serialize_generator/CHANGELOG.md
index 76492909..dd895869 100644
--- a/angel_serialize_generator/CHANGELOG.md
+++ b/angel_serialize_generator/CHANGELOG.md
@@ -1,6 +1,8 @@
 # 2.1.0
 * Removed dependency on `package:id`.
 * Update dependencies for Dart2Stable.
+* `jsonModelBuilder` now uses `SharedPartBuilder`, rather than
+`PartBuilder`.
 
 # 2.0.10
 * Generate `XFields.allFields` constant.
diff --git a/angel_serialize_generator/build.yaml b/angel_serialize_generator/build.yaml
index 6d8b75f4..2885ea5d 100644
--- a/angel_serialize_generator/build.yaml
+++ b/angel_serialize_generator/build.yaml
@@ -10,11 +10,12 @@ builders:
     build_to: source
     build_extensions:
       .dart:
-        - ".g.dart"
+        - "angel_serialize.g.part"
         - ".serializer.g.dart"
         - ".d.ts"
     required_inputs:
       - .dart
+    applies_builders: ["source_gen|combining_builder"]
 targets:
   _book:
     sources:
diff --git a/angel_serialize_generator/lib/angel_serialize_generator.dart b/angel_serialize_generator/lib/angel_serialize_generator.dart
index 076f46ce..747fb024 100644
--- a/angel_serialize_generator/lib/angel_serialize_generator.dart
+++ b/angel_serialize_generator/lib/angel_serialize_generator.dart
@@ -23,10 +23,8 @@ part 'serialize.dart';
 part 'typescript.dart';
 
 Builder jsonModelBuilder(_) {
-  return new PartBuilder(
-    const [const JsonModelGenerator()],
-    '.g.dart',
-  );
+  return new SharedPartBuilder(
+      const [const JsonModelGenerator()], 'angel_serialize');
 }
 
 Builder serializerBuilder(_) {