diff --git a/plugins/http2_adapter/CHANGELOG.md b/plugins/http2_adapter/CHANGELOG.md
index 1b6622feb..1cb60f918 100644
--- a/plugins/http2_adapter/CHANGELOG.md
+++ b/plugins/http2_adapter/CHANGELOG.md
@@ -4,6 +4,7 @@
 
 - Support non-TLS connection requests.
 - Improve the implementation of `receiveTimeout`.
+- Add more header value types implicit support.
 
 ## 2.3.2
 
diff --git a/plugins/http2_adapter/lib/src/http2_adapter.dart b/plugins/http2_adapter/lib/src/http2_adapter.dart
index b27b84745..a8eff0bcf 100644
--- a/plugins/http2_adapter/lib/src/http2_adapter.dart
+++ b/plugins/http2_adapter/lib/src/http2_adapter.dart
@@ -62,14 +62,17 @@ class Http2Adapter implements HttpClientAdapter {
 
     // Add custom headers
     headers.addAll(
-      options.headers.keys
-          .map(
-            (key) => Header.ascii(
-              key.toLowerCase(),
-              options.headers[key] as String? ?? '',
-            ),
-          )
-          .toList(),
+      options.headers.entries.map(
+        (entry) {
+          final String v;
+          if (entry.value is Iterable) {
+            v = entry.value.join(', ');
+          } else {
+            v = '${entry.value}';
+          }
+          return Header.ascii(entry.key.toLowerCase(), v);
+        },
+      ).toList(),
     );
 
     // Creates a new outgoing stream.
diff --git a/plugins/http2_adapter/test/http2_test.dart b/plugins/http2_adapter/test/http2_test.dart
index 972558317..43a560875 100644
--- a/plugins/http2_adapter/test/http2_test.dart
+++ b/plugins/http2_adapter/test/http2_test.dart
@@ -133,4 +133,29 @@ void main() {
     final res = await dio.get('absolute-redirect/2');
     expect(res.statusCode, 200);
   });
+
+  test('header value types implicit support', () async {
+    final dio = Dio()
+      ..options.baseUrl = 'https://httpbun.com/'
+      ..httpClientAdapter = Http2Adapter(ConnectionManager());
+
+    final res = await dio.post(
+      'post',
+      data: 'TEST',
+      options: Options(
+        headers: {
+          'ListKey': ['1', '2'],
+          'StringKey': '1',
+          'NumKey': 2,
+          'BooleanKey': false,
+        },
+      ),
+    );
+    final content = res.data.toString();
+    expect(content, contains('TEST'));
+    expect(content, contains('Listkey: 1, 2'));
+    expect(content, contains('Stringkey: 1'));
+    expect(content, contains('Numkey: 2'));
+    expect(content, contains('Booleankey: false'));
+  });
 }