diff --git a/src/config.rs b/src/config.rs
index 98da773..07c9114 100644
--- a/src/config.rs
+++ b/src/config.rs
@@ -9,7 +9,7 @@ pub const PAYLOAD_LIMIT: usize = 10_000_000;
 pub const PROXY_TIMEOUT: u64 = 15;
 
 pub const CONFIG_FILE: &str = "./config.toml";
-pub const CONFIG_VERSION: u8 = 1;
+pub const CONFIG_VERSION: u8 = 2;
 
 pub const ADJ_LIST_FILE: &str = "./adj-list.txt";
 pub const NAME_LIST_FILE: &str = "./name-list.txt";
@@ -49,6 +49,7 @@ pub struct Config {
     pub admin_password: String,
     pub prune_days: u16,
     pub debug_mode: bool,
+    pub cookie_key: String,
     pub config_version: u8,
 }
 
@@ -64,7 +65,7 @@ impl Config {
         conffile
             .read_to_string(&mut confstr)
             .expect("Couldn't read config to string");
-        toml::from_str(&confstr).expect("Couldn't deserialize the config")
+        toml::from_str(&confstr).expect("Couldn't deserialize the config. Please update at https://git.42l.fr/neil/sncf/wiki/Upgrade-from-a-previous-version --- Error")
     }
 
     // if config.config_version doesn't match the hardcoded version,