diff --git a/src/mito2/src/worker/handle_write.rs b/src/mito2/src/worker/handle_write.rs
index 9b7693710b32..ca9a1b31a391 100644
--- a/src/mito2/src/worker/handle_write.rs
+++ b/src/mito2/src/worker/handle_write.rs
@@ -239,7 +239,7 @@ fn check_op_type(append_mode: bool, request: &WriteRequest) -> Result<()> {
             request.op_type == OpType::Put,
             InvalidRequestSnafu {
                 region_id: request.region_id,
-                reason: "Only put is allowed under append mode",
+                reason: "DELETE is not allowed under append mode",
             }
         );
     }
diff --git a/tests/cases/standalone/common/insert/append_mode.result b/tests/cases/standalone/common/insert/append_mode.result
index a9b4d5aa51da..4fe1166ae6e2 100644
--- a/tests/cases/standalone/common/insert/append_mode.result
+++ b/tests/cases/standalone/common/insert/append_mode.result
@@ -29,6 +29,11 @@ SELECT * from append_mode_on ORDER BY host, ts;
 | host2 | 1970-01-01T00:00:00.001 | 1.0 |
 +-------+-------------------------+-----+
 
+-- SQLNESS REPLACE (region\s\d+\(\d+\,\s\d+\)) region
+DELETE FROM append_mode_on WHERE host = 'host1';
+
+Error: 1004(InvalidArguments), Invalid request to region, reason: DELETE is not allowed under append mode
+
 create table if not exists append_mode_off(
     host string,
     ts timestamp,
diff --git a/tests/cases/standalone/common/insert/append_mode.sql b/tests/cases/standalone/common/insert/append_mode.sql
index 1e128c440f1b..a27a66f4e013 100644
--- a/tests/cases/standalone/common/insert/append_mode.sql
+++ b/tests/cases/standalone/common/insert/append_mode.sql
@@ -14,6 +14,9 @@ INSERT INTO append_mode_on VALUES ('host1',0, 0), ('host2', 1, 1,);
 
 SELECT * from append_mode_on ORDER BY host, ts;
 
+-- SQLNESS REPLACE (region\s\d+\(\d+\,\s\d+\)) region
+DELETE FROM append_mode_on WHERE host = 'host1';
+
 create table if not exists append_mode_off(
     host string,
     ts timestamp,