diff --git a/test/byte_accumulator_sink_test.dart b/test/byte_accumulator_sink_test.dart
index 123baa8e74a31..332e71cae1f9e 100644
--- a/test/byte_accumulator_sink_test.dart
+++ b/test/byte_accumulator_sink_test.dart
@@ -6,7 +6,7 @@ import 'package:convert/convert.dart';
 import 'package:test/test.dart';
 
 void main() {
-  var sink;
+  ByteAccumulatorSink sink;
   setUp(() {
     sink = new ByteAccumulatorSink();
   });