diff --git a/script/tool/test/util.dart b/script/tool/test/util.dart
index a8cb527d9238..913242b6ea69 100644
--- a/script/tool/test/util.dart
+++ b/script/tool/test/util.dart
@@ -453,7 +453,7 @@ class ProcessCall {
   final String? workingDir;
 
   @override
-  bool operator ==(dynamic other) {
+  bool operator ==(Object other) {
     return other is ProcessCall &&
         executable == other.executable &&
         listsEqual(args, other.args) &&