diff --git a/mclog2psql/main.py b/mclog2psql/main.py
index e17f43d..16ffa65 100644
--- a/mclog2psql/main.py
+++ b/mclog2psql/main.py
@@ -88,7 +88,7 @@ def insert_sessions_into_db(
                 CREATE TABLE IF NOT EXISTS "minecraft_login_sessions"(
                   "username" TEXT NOT NULL,
                   "start" TIMESTAMP NOT NULL,
-                  "duration" INTEGER NOT NULL,
+                  "duration" BIGINT NOT NULL CHECK (duration >= 0),
                   PRIMARY KEY ("username", "start")
                 )
               """)