diff --git a/im-center-server/src/main/java/cn/axzo/im/group/message/GroupMessageSyncService.java b/im-center-server/src/main/java/cn/axzo/im/group/message/GroupMessageSyncService.java
index 8bcc968..67459d2 100644
--- a/im-center-server/src/main/java/cn/axzo/im/group/message/GroupMessageSyncService.java
+++ b/im-center-server/src/main/java/cn/axzo/im/group/message/GroupMessageSyncService.java
@@ -111,7 +111,7 @@ public class GroupMessageSyncService {
                         .eq(GroupMessage::getTid, tid));
         return groupMessage == null
                 ? Optional.empty()
-                : Optional.of(groupMessage.getSendTime());
+                : Optional.ofNullable(groupMessage.getSendTime());
     }
 
     NimGroupGetMessagesResponse getGroupMessages(NimGroupGetMessagesRequest request) {