diff --git a/files/__main__.py b/files/__main__.py
index 16c1793cc..e76d36703 100644
--- a/files/__main__.py
+++ b/files/__main__.py
@@ -94,7 +94,7 @@ app.config['SQLALCHEMY_TRACK_MODIFICATIONS'] = False
 app.config['DATABASE_URL'] = environ.get("DATABASE_URL", "postgresql://postgres@localhost:5432")
 app.config['SECRET_KEY'] = environ.get('MASTER_KEY')
 app.config["SERVER_NAME"] = environ.get("DOMAIN").strip()
-app.config['SEND_FILE_MAX_AGE_DEFAULT'] = 3153600
+app.config['SEND_FILE_MAX_AGE_DEFAULT'] = 0 if app.debug else 3153600
 app.config["SESSION_COOKIE_NAME"] = "session_" + environ.get("SITE_ID").strip().lower()
 app.config["VERSION"] = "1.0.0"
 app.config['MAX_CONTENT_LENGTH'] = 16 * 1024 * 1024