diff --git a/lib/src/usage_impl.dart b/lib/src/usage_impl.dart
index c94b4e5..73acc24 100644
--- a/lib/src/usage_impl.dart
+++ b/lib/src/usage_impl.dart
@@ -202,7 +202,7 @@
     Future f = Future.wait(_futures).catchError((e) => null);
 
     if (timeout != null) {
-      f = f.timeout(timeout, onTimeout: () => null);
+      f = f.timeout(timeout, onTimeout: () => []);
     }
 
     return f;
diff --git a/pubspec.yaml b/pubspec.yaml
index 257679b..9613c34 100644
--- a/pubspec.yaml
+++ b/pubspec.yaml
@@ -15,4 +15,4 @@
 
 dev_dependencies:
   pedantic: ^1.9.0
-  test: ^1.0.0
+  test: ^1.16.0-nullsafety