diff --git a/java/tsfile/src/main/java/org/apache/tsfile/read/common/type/UnknownType.java b/java/tsfile/src/main/java/org/apache/tsfile/read/common/type/UnknownType.java
index 818019cf7..802165dc8 100644
--- a/java/tsfile/src/main/java/org/apache/tsfile/read/common/type/UnknownType.java
+++ b/java/tsfile/src/main/java/org/apache/tsfile/read/common/type/UnknownType.java
@@ -28,7 +28,7 @@
 
 import static org.apache.tsfile.utils.Preconditions.checkArgument;
 
-public class UnknownType implements Type {
+public class UnknownType extends AbstractType {
   public static final UnknownType UNKNOWN = new UnknownType();
   public static final String NAME = "unknown";