diff --git a/lib/src/bones_api_utils_timedmap.dart b/lib/src/bones_api_utils_timedmap.dart
index b4c87a0..cdae827 100644
--- a/lib/src/bones_api_utils_timedmap.dart
+++ b/lib/src/bones_api_utils_timedmap.dart
@@ -5,8 +5,8 @@ class TimedMap<K, V> implements Map<K, V> {
   /// The key timeout. When a key is put, it expires after the timeout [Duration].
   final Duration keyTimeout;
 
-  final bool? Function(Object? key, Duration elapsedTime, Duration keyTimeout)?
-      keyTimeoutChecker;
+  final bool? Function(TimedMap timedMap, Object? key, Duration elapsedTime,
+      Duration keyTimeout)? keyTimeoutChecker;
 
   TimedMap(this.keyTimeout, [Map<K, V>? map, this.keyTimeoutChecker]) {
     if (map != null) {
@@ -140,7 +140,7 @@ class TimedMap<K, V> implements Map<K, V> {
     keyTimeout ??= this.keyTimeout;
 
     if (keyTimeoutChecker != null) {
-      var expired = keyTimeoutChecker(key, elapsedTime, keyTimeout);
+      var expired = keyTimeoutChecker(this, key, elapsedTime, keyTimeout);
       if (expired != null) {
         return expired;
       }
diff --git a/test/bones_api_utils_test.dart b/test/bones_api_utils_test.dart
index b5772ab..6230c30 100644
--- a/test/bones_api_utils_test.dart
+++ b/test/bones_api_utils_test.dart
@@ -433,6 +433,34 @@ void main() {
 
       expect(m.length, equals(0));
     });
+
+    test('keyTimeoutChecker', () async {
+      final checks = <String>[];
+
+      var m = TimedMap<String, int>(Duration(seconds: 1), null, (tm, k, t, to) {
+        checks.add('$k,${to.inMilliseconds}');
+        if (k == 'b') return false;
+        return null;
+      });
+
+      m.put('a', 1);
+      m.put('b', 2);
+
+      expect(m.length, equals(2));
+      expect(checks, isEmpty);
+
+      m.checkAllEntries();
+
+      expect(m.length, equals(2));
+      expect(checks, equals(['a,1000', 'b,1000']));
+
+      await Future.delayed(Duration(milliseconds: 1100));
+
+      m.checkAllEntries();
+
+      expect(m, equals({'b': 2}));
+      expect(checks, equals(['a,1000', 'b,1000', 'a,1000', 'b,1000']));
+    });
   });
 
   group('PositionalFields', () {