diff --git a/src/datanode/src/alive_keeper.rs b/src/datanode/src/alive_keeper.rs
index 5f5fe9be1395..ae6e18a989c6 100644
--- a/src/datanode/src/alive_keeper.rs
+++ b/src/datanode/src/alive_keeper.rs
@@ -461,8 +461,8 @@ mod test {
         // wait for countdown task to finish
         let before_await = Instant::now();
         let (finish_instant, result) = rx.await.unwrap();
-        // the mock region server cannot close the region
-        assert_eq!(result, Some(false));
+        // it returns `RegionNotFound`
+        assert_eq!(result, Some(true));
         // this task should be finished after 5 * heartbeat_interval_millis
         // we assert 4 times here
         assert!(
diff --git a/src/datanode/src/error.rs b/src/datanode/src/error.rs
index 62828c996f24..3eb3d232c5aa 100644
--- a/src/datanode/src/error.rs
+++ b/src/datanode/src/error.rs
@@ -518,11 +518,12 @@ impl ErrorExt for Error {
             | MissingInsertBody { .. }
             | ShutdownInstance { .. }
             | JoinTask { .. }
-            | RegionNotFound { .. }
             | RegionEngineNotFound { .. }
             | UnsupportedOutput { .. }
             | GetRegionMetadata { .. } => StatusCode::Internal,
 
+            RegionNotFound { .. } => StatusCode::RegionNotFound,
+
             StartServer { source, .. }
             | ShutdownServer { source, .. }
             | WaitForGrpcServing { source, .. } => source.status_code(),