diff --git a/snarl/tracker.py b/snarl/tracker.py
index 8e24c69..05c7e2d 100644
--- a/snarl/tracker.py
+++ b/snarl/tracker.py
@@ -1,4 +1,4 @@
-from typing import List, Set, ClassVar, Optional
+from typing import List, Set, ClassVar, Optional, Dict
 from collections import defaultdict
 from dataclasses import dataclass