diff --git a/files/routes/posts.py b/files/routes/posts.py
index 7ef2189dcb..b45f4ee113 100644
--- a/files/routes/posts.py
+++ b/files/routes/posts.py
@@ -523,6 +523,8 @@ def is_repost():
 @limiter.limit(POST_RATE_LIMIT, key_func=get_ID)
 @auth_required
 def submit_post(v:User, sub=None):
+	if request.content_length > 500 * 1024 * 1024:
+		return {"error": "Max file size is 500 MB."}, 413
 
 	url = request.values.get("url", "").strip()