diff --git a/dio_cache_interceptor/lib/src/extension/response_extension.dart b/dio_cache_interceptor/lib/src/extension/response_extension.dart
index d372919..602fbab 100644
--- a/dio_cache_interceptor/lib/src/extension/response_extension.dart
+++ b/dio_cache_interceptor/lib/src/extension/response_extension.dart
@@ -49,6 +49,7 @@ extension ResponseExtension on Response {
     }
 
     updateNonNullHeader(cacheControlHeader);
+    updateNonNullHeader(ageHeader);
     updateNonNullHeader(dateHeader);
     updateNonNullHeader(etagHeader);
     updateNonNullHeader(lastModifiedHeader);
diff --git a/dio_cache_interceptor/test/cache_interceptor_test.dart b/dio_cache_interceptor/test/cache_interceptor_test.dart
index b4e378f..128f5f7 100644
--- a/dio_cache_interceptor/test/cache_interceptor_test.dart
+++ b/dio_cache_interceptor/test/cache_interceptor_test.dart
@@ -96,12 +96,14 @@ void main() {
     final resp = await dio.get('${MockHttpClientAdapter.mockBase}/ok');
     final key = resp.extra[extraCacheKey];
     expect(await store.exists(key), isTrue);
+    expect(resp.headers[ageHeader], equals(['1']));
 
     var resp304 = await dio.get('${MockHttpClientAdapter.mockBase}/ok');
     expect(resp304.statusCode, equals(200));
     expect(resp.data['path'], equals('/ok'));
     expect(resp304.extra[extraCacheKey], equals(key));
     expect(resp304.extra[extraFromNetworkKey], isTrue);
+    expect(resp304.headers[ageHeader], equals(['10']));
     expect(resp304.headers['etag'], equals(['5678']));
   });
 
diff --git a/dio_cache_interceptor/test/mock_httpclient_adapter.dart b/dio_cache_interceptor/test/mock_httpclient_adapter.dart
index 617d2ca..397616d 100644
--- a/dio_cache_interceptor/test/mock_httpclient_adapter.dart
+++ b/dio_cache_interceptor/test/mock_httpclient_adapter.dart
@@ -26,6 +26,7 @@ class MockHttpClientAdapter implements HttpClientAdapter {
             304,
             headers: {
               Headers.contentTypeHeader: [Headers.jsonContentType],
+              ageHeader: ['10'],
               'etag': ['5678'],
             },
           );
@@ -44,11 +45,12 @@ class MockHttpClientAdapter implements HttpClientAdapter {
         return ResponseBody.fromString(
           jsonEncode({'path': uri.path}),
           200,
-          headers: {
-            Headers.contentTypeHeader: [Headers.jsonContentType],
-            'etag': ['1234'],
-          },
-        );
+        headers: {
+          Headers.contentTypeHeader: [Headers.jsonContentType],
+          ageHeader: ['1'],
+          'etag': ['1234'],
+        },
+      );
       case '/ok-nodirective':
         return ResponseBody.fromString(
           jsonEncode({'path': uri.path}),
diff --git a/http_cache_client/lib/src/extension/response_extension.dart b/http_cache_client/lib/src/extension/response_extension.dart
index bbda281..cd7af2f 100644
--- a/http_cache_client/lib/src/extension/response_extension.dart
+++ b/http_cache_client/lib/src/extension/response_extension.dart
@@ -46,6 +46,7 @@ extension ResponseExtension on http.Response {
     }
 
     updateNonNullHeader(cacheControlHeader);
+    updateNonNullHeader(ageHeader);
     updateNonNullHeader(dateHeader);
     updateNonNullHeader(etagHeader);
     updateNonNullHeader(lastModifiedHeader);
diff --git a/http_cache_client/test/http_cache_client_cache_call_mocks.dart b/http_cache_client/test/http_cache_client_cache_call_mocks.dart
index 694bd7a..70cc5a1 100644
--- a/http_cache_client/test/http_cache_client_cache_call_mocks.dart
+++ b/http_cache_client/test/http_cache_client_cache_call_mocks.dart
@@ -15,10 +15,15 @@ Future<http.Response> getOk(
     MockClient(
       (request) async => http.Response(
         jsonEncode({'path': request.url.path}),
-        request.headers.containsKey('x-err') ? 500 : 200,
+        request.headers.containsKey('x-err')
+            ? 500
+            : request.headers.containsKey(ifNoneMatchHeader)
+                ? 304
+                : 200,
         headers: {
           contentTypeHeader: jsonContentType,
-          etagHeader: '1234',
+          etagHeader: request.headers.containsKey(ifNoneMatchHeader) ? '5678' : '1234',
+          ageHeader: request.headers.containsKey(ifNoneMatchHeader) ? '10' : '1',
           dateHeader: HttpDate.format(DateTime.now()),
         },
         request: request,
diff --git a/http_cache_client/test/http_cache_client_cache_test.dart b/http_cache_client/test/http_cache_client_cache_test.dart
index 8c38ef2..1942fb0 100644
--- a/http_cache_client/test/http_cache_client_cache_test.dart
+++ b/http_cache_client/test/http_cache_client_cache_test.dart
@@ -50,16 +50,16 @@ void main() {
     final key = options.keyBuilder(url: resp.request!.url);
     expect(await store.exists(key), isTrue);
     final cacheResp1 = await store.get(key);
+    expect(resp.headers[ageHeader], equals('1'));
 
     final resp304 = await getOk(options);
     expect(resp304.statusCode, equals(200));
     final cacheResp2 = await store.get(key);
-
-    expect(
-        cacheResp1!.copyWith(
-            requestDate: cacheResp2!.requestDate,
-            responseDate: cacheResp2.responseDate),
-        equals(cacheResp2));
+    expect(resp304.headers[ageHeader], equals('10'));
+    expect(cacheResp1, isNotNull);
+    expect(cacheResp2, isNotNull);
+    expect(cacheResp2!.eTag, equals('5678'));
+    expect(cacheResp2.getHeaders()[ageHeader], equals('10'));
   });
 
   test('Fetch noCache policy', () async {