diff --git a/pkgs/ffi/CHANGELOG.md b/pkgs/ffi/CHANGELOG.md
index 06f45b86ec..53b1cac50b 100644
--- a/pkgs/ffi/CHANGELOG.md
+++ b/pkgs/ffi/CHANGELOG.md
@@ -1,6 +1,7 @@
-## 2.1.5-wip
+## 2.1.5
 
 - Update to the latest lints.
+- Add default parameter names for callbacks.
 
 ## 2.1.4
 
diff --git a/pkgs/ffi/lib/src/arena.dart b/pkgs/ffi/lib/src/arena.dart
index 37861370c0..1b3f26fb42 100644
--- a/pkgs/ffi/lib/src/arena.dart
+++ b/pkgs/ffi/lib/src/arena.dart
@@ -60,7 +60,7 @@ class Arena implements Allocator {
   ///
   /// Returns [resource] again, to allow for easily inserting
   /// `arena.using(resource, ...)` where the resource is allocated.
-  T using<T>(T resource, void Function(T) releaseCallback) {
+  T using<T>(T resource, void Function(T res) releaseCallback) {
     _ensureInUse();
     releaseCallback = Zone.current.bindUnaryCallback(releaseCallback);
     _managedResourceReleaseCallbacks.add(() => releaseCallback(resource));
@@ -118,7 +118,7 @@ class Arena implements Allocator {
 /// If the isolate is shut down, through `Isolate.kill()`, resources are _not_
 /// cleaned up.
 R using<R>(
-  R Function(Arena) computation, [
+  R Function(Arena arena) computation, [
   Allocator wrappedAllocator = calloc,
 ]) {
   final arena = Arena(wrappedAllocator);