diff --git a/README.md b/README.md
index eb611ef2..13973811 100644
--- a/README.md
+++ b/README.md
@@ -53,6 +53,7 @@ library angel_serialize.test.models.book;
 
 import 'package:angel_framework/common.dart';
 import 'package:angel_serialize/angel_serialize.dart';
+import 'package:collection/collection.dart';
 part 'book.g.dart';
 
 @serializable
diff --git a/angel_serialize_generator/CHANGELOG.md b/angel_serialize_generator/CHANGELOG.md
index 0574301a..2d180d8e 100644
--- a/angel_serialize_generator/CHANGELOG.md
+++ b/angel_serialize_generator/CHANGELOG.md
@@ -1,3 +1,6 @@
+# 2.0.7
+* Create unmodifiable Lists and Maps.
+
 # 2.0.6
 * Support for using `abstract` to create immutable model classes.
 * Add support for custom constructor parameters.
diff --git a/angel_serialize_generator/lib/angel_serialize_generator.dart b/angel_serialize_generator/lib/angel_serialize_generator.dart
index 35021637..e3f2b2a1 100644
--- a/angel_serialize_generator/lib/angel_serialize_generator.dart
+++ b/angel_serialize_generator/lib/angel_serialize_generator.dart
@@ -60,16 +60,21 @@ bool isModelClass(DartType t) {
   }
 }
 
+bool isListOrMapType(DartType t) {
+  return const TypeChecker.fromRuntime(List).isAssignableFromType(t) ||
+      const TypeChecker.fromRuntime(Map).isAssignableFromType(t);
+}
+
 /// Determines if a [DartType] is a `List` with the first type argument being a `Model`.
 bool isListModelType(InterfaceType t) {
-  return t.name == 'List' &&
+  return const TypeChecker.fromRuntime(List).isAssignableFromType(t) &&
       t.typeArguments.length == 1 &&
       isModelClass(t.typeArguments[0]);
 }
 
 /// Determines if a [DartType] is a `Map` with the second type argument being a `Model`.
 bool isMapToModelType(InterfaceType t) {
-  return t.name == 'Map' &&
+  return const TypeChecker.fromRuntime(Map).isAssignableFromType(t) &&
       t.typeArguments.length == 2 &&
       isModelClass(t.typeArguments[1]);
 }
diff --git a/angel_serialize_generator/lib/model.dart b/angel_serialize_generator/lib/model.dart
index 60e9957a..6bd676f9 100644
--- a/angel_serialize_generator/lib/model.dart
+++ b/angel_serialize_generator/lib/model.dart
@@ -63,23 +63,43 @@ class JsonModelGenerator extends GeneratorForAnnotation<Serializable> {
       BuildContext ctx, ClassBuilder clazz, LibraryBuilder file) {
     clazz.constructors.add(new Constructor((constructor) {
       // Add all `super` params
-      if (ctx.constructorParameters.isNotEmpty) {
-        for (var param in ctx.constructorParameters) {
-          constructor.requiredParameters.add(new Parameter((b) => b
-            ..name = param.name
-            ..type = convertTypeReference(param.type)));
-        }
 
-        constructor.initializers.add(new Code(
-            'super(${ctx.constructorParameters.map((p) => p.name).join(',')})'));
+      for (var param in ctx.constructorParameters) {
+        constructor.requiredParameters.add(new Parameter((b) => b
+          ..name = param.name
+          ..type = convertTypeReference(param.type)));
+      }
+
+      for (var field in ctx.fields) {
+        if (isListOrMapType(field.type)) {
+          String typeName = const TypeChecker.fromRuntime(List)
+                  .isAssignableFromType(field.type)
+              ? 'List'
+              : 'Map';
+          var defaultValue = typeName == 'List' ? '[]' : '{}';
+          constructor.initializers.add(new Code('''
+              this.${field.name} =
+                new $typeName.unmodifiable(${field.name} ?? $defaultValue)'''));
+        }
+      }
+
+      if (ctx.constructorParameters.isNotEmpty) {
+        constructor.initializers.add(
+            new Code('super(${ctx.constructorParameters.map((p) => p.name).join(
+                ',')})'));
       }
 
       for (var field in ctx.fields) {
         constructor.optionalParameters.add(new Parameter((b) {
           b
             ..name = field.name
-            ..named = true
-            ..toThis = true;
+            ..named = true;
+
+          if (!isListOrMapType(field.type))
+            b.toThis = true;
+          else {
+            b.type = convertTypeReference(field.type);
+          }
         }));
       }
     }));
@@ -141,9 +161,11 @@ class JsonModelGenerator extends GeneratorForAnnotation<Serializable> {
       if (it.typeParameters.length == 2) {
         var keq = generateEquality(it.typeArguments[0]),
             veq = generateEquality(it.typeArguments[1]);
-        return 'const MapEquality<${it.typeArguments[0].name}, ${it.typeArguments[1].name}>(keys: $keq, values: $veq)';
+        return 'const MapEquality<${it.typeArguments[0].name}, ${it
+            .typeArguments[1].name}>(keys: $keq, values: $veq)';
       } else
-        return 'const MapEquality()<${it.typeArguments[0].name}, ${it.typeArguments[1].name}>';
+        return 'const MapEquality()<${it.typeArguments[0].name}, ${it
+            .typeArguments[1].name}>';
     }
 
     return nullable ? null : 'const DefaultEquality<${type.name}>()';
diff --git a/angel_serialize_generator/lib/serialize.dart b/angel_serialize_generator/lib/serialize.dart
index d0abab99..6c04d39f 100644
--- a/angel_serialize_generator/lib/serialize.dart
+++ b/angel_serialize_generator/lib/serialize.dart
@@ -169,17 +169,17 @@ class SerializerGenerator extends GeneratorForAnnotation<Serializable> {
           if (isListModelType(t)) {
             var rc = new ReCase(t.typeArguments[0].name);
             deserializedRepresentation = "map['$alias'] is Iterable"
-                " ? map['$alias'].map(${rc
-                .pascalCase}Serializer.fromMap).toList()"
+                " ? new List.unmodifiable(map['$alias'].map(${rc
+                .pascalCase}Serializer.fromMap))"
                 " : null";
           } else if (isMapToModelType(t)) {
             var rc = new ReCase(t.typeArguments[1].name);
             deserializedRepresentation = '''
                 map['$alias'] is Map
-                  ? map['$alias'].keys.fold({}, (out, key) {
+                  ? new Map.unmodifiable(map['$alias'].keys.fold({}, (out, key) {
                        return out..[key] = ${rc
                 .pascalCase}Serializer.fromMap(map['$alias'][key]);
-                    })
+                    }))
                   : null
             ''';
           }
diff --git a/angel_serialize_generator/test/models/author.g.dart b/angel_serialize_generator/test/models/author.g.dart
index 24dcf596..a14db13e 100644
--- a/angel_serialize_generator/test/models/author.g.dart
+++ b/angel_serialize_generator/test/models/author.g.dart
@@ -11,12 +11,13 @@ class Author extends _Author {
       {this.id,
       this.name,
       this.age,
-      this.books,
+      List<Book> books,
       this.newestBook,
       this.secret,
       this.obscured,
       this.createdAt,
-      this.updatedAt});
+      this.updatedAt})
+      : this.books = new List.unmodifiable(books ?? []);
 
   @override
   final String id;
@@ -87,7 +88,9 @@ class Author extends _Author {
 }
 
 class Library extends _Library {
-  Library({this.id, this.collection, this.createdAt, this.updatedAt});
+  Library(
+      {this.id, Map<String, Book> collection, this.createdAt, this.updatedAt})
+      : this.collection = new Map.unmodifiable(collection ?? {});
 
   @override
   final String id;
@@ -132,12 +135,13 @@ class Library extends _Library {
 class Bookmark extends _Bookmark {
   Bookmark(Book book,
       {this.id,
-      this.history,
+      List<int> history,
       this.page,
       this.comment,
       this.createdAt,
       this.updatedAt})
-      : super(book);
+      : this.history = new List.unmodifiable(history ?? []),
+        super(book);
 
   @override
   final String id;
diff --git a/angel_serialize_generator/test/models/author.serializer.g.dart b/angel_serialize_generator/test/models/author.serializer.g.dart
index 2aadeddf..5747c076 100644
--- a/angel_serialize_generator/test/models/author.serializer.g.dart
+++ b/angel_serialize_generator/test/models/author.serializer.g.dart
@@ -13,7 +13,7 @@ abstract class AuthorSerializer {
         name: map['name'],
         age: map['age'],
         books: map['books'] is Iterable
-            ? map['books'].map(BookSerializer.fromMap).toList()
+            ? new List.unmodifiable(map['books'].map(BookSerializer.fromMap))
             : null,
         newestBook: map['newest_book'] != null
             ? BookSerializer.fromMap(map['newest_book'])
@@ -69,10 +69,10 @@ abstract class LibrarySerializer {
     return new Library(
         id: map['id'],
         collection: map['collection'] is Map
-            ? map['collection'].keys.fold({}, (out, key) {
+            ? new Map.unmodifiable(map['collection'].keys.fold({}, (out, key) {
                 return out
                   ..[key] = BookSerializer.fromMap(map['collection'][key]);
-              })
+              }))
             : null,
         createdAt: map['created_at'] != null
             ? (map['created_at'] is DateTime
diff --git a/angel_serialize_generator/test/models/book.g.dart b/angel_serialize_generator/test/models/book.g.dart
index 5c5bfbe9..ff9a997c 100644
--- a/angel_serialize_generator/test/models/book.g.dart
+++ b/angel_serialize_generator/test/models/book.g.dart
@@ -13,10 +13,11 @@ class Book extends _Book {
       this.title,
       this.description,
       this.pageCount,
-      this.notModels,
+      List<double> notModels,
       this.camelCaseString,
       this.createdAt,
-      this.updatedAt});
+      this.updatedAt})
+      : this.notModels = new List.unmodifiable(notModels ?? []);
 
   @override
   final String id;