diff --git a/CHANGELOG.md b/CHANGELOG.md
index 2104b9b..d490d9a 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,3 +1,7 @@
+## 5.0.3
+
+* Support 1.x releases of source_gen.
+
 ## 5.0.2
 
 * Support the latest build packages and dart_style.
diff --git a/lib/src/version.dart b/lib/src/version.dart
index 041813e..977890f 100644
--- a/lib/src/version.dart
+++ b/lib/src/version.dart
@@ -1 +1 @@
-const packageVersion = '5.0.2';
+const packageVersion = '5.0.3';
diff --git a/pubspec.yaml b/pubspec.yaml
index 5ecc027..dff34bf 100644
--- a/pubspec.yaml
+++ b/pubspec.yaml
@@ -1,5 +1,5 @@
 name: mockito
-version: 5.0.2
+version: 5.0.3
 
 description: A mock framework inspired by Mockito.
 homepage: https://github.com/dart-lang/mockito
@@ -16,7 +16,7 @@
   matcher: ^0.12.10
   meta: ^1.3.0
   path: ^1.8.0
-  source_gen: ^0.9.6
+  source_gen: '>=0.9.6 <2.0.0'
   test_api: '>=0.2.1 <0.4.0'
 
 dev_dependencies: