diff --git a/generate_ics.py b/generate_ics.py
index b440e37..bdea26c 100644
--- a/generate_ics.py
+++ b/generate_ics.py
@@ -79,5 +79,5 @@ def generate_ics(data, filename):
             name = "上班(补" + name + ")"
         cal.add_component(create_event(name, start, end))
 
-    with open(f"{filename}.ics", "wb") as ics:
+    with open(filename, "wb", encoding="utf8") as ics:
         ics.write(cal.to_ical())
diff --git a/update.py b/update.py
index a28bd5c..9d84a6e 100755
--- a/update.py
+++ b/update.py
@@ -71,7 +71,7 @@ def update_data(year: int) -> str:
             cls=CustomJSONEncoder,
         )
 
-        generate_ics(data, filename=f"{year}")
+        generate_ics(data, filename=f"{year}.ics")
     return filename
 
 
@@ -86,7 +86,8 @@ def update_holiday_ics(fr_year, to_year):
             big_days.extend(data.get("days"))
 
     generate_ics(
-        {"days": sorted(big_days, key=lambda x: x["date"])}, filename="holiday-cn"
+        {"days": sorted(big_days, key=lambda x: x["date"])},
+        filename="holiday-cn.ics",
     )