diff --git a/.analysis_options b/.analysis_options
new file mode 100644
index 0000000..a10d4c5
--- /dev/null
+++ b/.analysis_options
@@ -0,0 +1,2 @@
+analyzer:
+  strong-mode: true
diff --git a/CHANGELOG.md b/CHANGELOG.md
index 70f914b..96d4c2f 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,3 +1,7 @@
+## 1.2.4
+
+* Fix a strong-mode error.
+
 ## 1.2.3
 
 * Fix a bug in which `Pool.withResource()` could throw a `StateError` when
diff --git a/lib/pool.dart b/lib/pool.dart
index deb5333..faa9f0e 100644
--- a/lib/pool.dart
+++ b/lib/pool.dart
@@ -116,8 +116,8 @@
     // synchronously in case the pool is closed immediately afterwards. Async
     // functions have an asynchronous gap between calling and running the body,
     // and [close] could be called during that gap. See #3.
-    return request().then((resource) {
-      return new Future.sync(callback).whenComplete(resource.release);
+    return request().then/*<Future<T>>*/((resource) {
+      return new Future/*<T>*/.sync(callback).whenComplete(resource.release);
     });
   }
 
diff --git a/pubspec.yaml b/pubspec.yaml
index 58321cf..145df2b 100644
--- a/pubspec.yaml
+++ b/pubspec.yaml
@@ -1,5 +1,5 @@
 name: pool
-version: 1.2.3
+version: 1.2.4
 author: Dart Team <misc@dartlang.org>
 description: A class for managing a finite pool of resources.
 homepage: https://github.com/dart-lang/pool