diff --git a/backend/app/api/bx/reimburse.py b/backend/app/api/bx/reimburse.py
index 3f57ffd47..1c6d4c09b 100644
--- a/backend/app/api/bx/reimburse.py
+++ b/backend/app/api/bx/reimburse.py
@@ -3,7 +3,7 @@ from datetime import date as date_cls
 from typing import List, Optional
 from urllib.parse import quote
 
-from fastapi import APIRouter, Depends, File, HTTPException, UploadFile, status
+from fastapi import APIRouter, Depends, File, HTTPException, Query, UploadFile, status
 from fastapi.responses import StreamingResponse
 from sqlalchemy import or_
 from sqlalchemy.orm import Session
@@ -192,7 +192,7 @@ def list_reimburses(
 @router.get("/my", response_model=ApiResponse[PagedData[ReimburseApplyOut]])
 def my_reimburses(
     page: int = 1,
-    pageSize: int = 10,
+    pageSize: int = Query(10, ge=1, le=500),
     status: Optional[str] = None,
     keyword: str = "",
     expenseName: Optional[str] = None,
diff --git a/backend/tests/test_bx_reimburse_my_page_size.py b/backend/tests/test_bx_reimburse_my_page_size.py
new file mode 100644
index 000000000..e0056d549
--- /dev/null
+++ b/backend/tests/test_bx_reimburse_my_page_size.py
@@ -0,0 +1,15 @@
+import inspect
+
+from fastapi.params import Query as QueryParam
+
+from app.api.bx.reimburse import my_reimburses
+
+
+def test_my_reimburses_page_size_query_bounds():
+    param = inspect.signature(my_reimburses).parameters["pageSize"]
+    q = param.default
+    assert isinstance(q, QueryParam)
+    attrs = q._attributes_set
+    assert attrs["ge"] == 1
+    assert attrs["le"] == 500
+    assert q.default == 10