diff --git a/sdk/src/main/java/cn/wildfirechat/sdk/messagecontent/UnknownMessageContent.java b/sdk/src/main/java/cn/wildfirechat/sdk/messagecontent/UnknownMessageContent.java
index a9c5a967..c7dc9cba 100644
--- a/sdk/src/main/java/cn/wildfirechat/sdk/messagecontent/UnknownMessageContent.java
+++ b/sdk/src/main/java/cn/wildfirechat/sdk/messagecontent/UnknownMessageContent.java
@@ -12,7 +12,7 @@ public class UnknownMessageContent extends MessageContent {
 
     @Override
     public int getContentType() {
-        return ProtoConstants.ContentType.Text;
+        return ProtoConstants.ContentType.Unknown;
     }
 
     @Override