diff --git a/backend/pyproject.toml b/backend/pyproject.toml
index c6f02b17..bb680739 100644
--- a/backend/pyproject.toml
+++ b/backend/pyproject.toml
@@ -8,6 +8,7 @@ dependencies = [
     "fastapi>=0.121",
     "uvicorn[standard]>=0.34.2",
     "arq>=0.26.3",
+    "croniter>=1.4.0",
     "yuxi",
 ]
 [tool.ruff]