diff --git a/crates/store/src/calendar.rs b/crates/store/src/calendar.rs
index 47c2842..445cb16 100644
--- a/crates/store/src/calendar.rs
+++ b/crates/store/src/calendar.rs
@@ -49,15 +49,15 @@ pub trait CalendarStore: Send + Sync + 'static {
 }
 
 #[derive(Debug, Deserialize, Serialize)]
-pub struct JsonCalendarStore {
+pub struct TomlCalendarStore {
     calendars: HashMap<String, Calendar>,
-    events: HashMap<String, Event>,
+    events: HashMap<String, HashMap<String, Event>>,
     path: String,
 }
 
-impl JsonCalendarStore {
+impl TomlCalendarStore {
     pub fn new(path: String) -> Self {
-        JsonCalendarStore {
+        TomlCalendarStore {
             calendars: HashMap::new(),
             events: HashMap::new(),
             path,
@@ -66,8 +66,8 @@ impl JsonCalendarStore {
 
     pub async fn save(&self) -> Result<()> {
         let mut file = File::create(&self.path).await?;
-        let json = serde_json::to_string_pretty(&self)?;
-        file.write_all(json.as_bytes()).await?;
+        let output = toml::to_string_pretty(&self)?;
+        file.write_all(output.as_bytes()).await?;
         Ok(())
     }
 }
diff --git a/src/config.rs b/src/config.rs
index 5b3623b..0618642 100644
--- a/src/config.rs
+++ b/src/config.rs
@@ -1,14 +1,14 @@
 use serde::{Deserialize, Serialize};
 
 #[derive(Debug, Deserialize, Serialize)]
-pub struct JsonCalendarStoreConfig {
+pub struct TomlCalendarStoreConfig {
     pub db_path: String,
 }
 
 #[derive(Debug, Deserialize, Serialize)]
 #[serde(tag = "backend", rename_all = "snake_case")]
 pub enum CalendarStoreConfig {
-    Json(JsonCalendarStoreConfig),
+    Toml(TomlCalendarStoreConfig),
 }
 
 #[derive(Debug, Deserialize, Serialize)]
diff --git a/src/main.rs b/src/main.rs
index 4419756..72bec96 100644
--- a/src/main.rs
+++ b/src/main.rs
@@ -6,11 +6,11 @@ use actix_web::middleware::{Logger, NormalizePath};
 use actix_web::{web, App, HttpServer};
 use anyhow::Result;
 use clap::Parser;
-use config::{CalendarStoreConfig, JsonCalendarStoreConfig};
+use config::{CalendarStoreConfig, TomlCalendarStoreConfig};
 use rustical_api::configure_api;
 use rustical_dav::{configure_dav, configure_well_known};
 use rustical_frontend::configure_frontend;
-use rustical_store::calendar::JsonCalendarStore;
+use rustical_store::calendar::TomlCalendarStore;
 use tokio::sync::RwLock;
 
 mod config;
@@ -30,10 +30,10 @@ async fn main() -> Result<()> {
     let config: Config = toml::from_str(&fs::read_to_string(&args.config_file)?)?;
 
     let cal_store = Arc::new(RwLock::new(match &config.calendar_store {
-        CalendarStoreConfig::Json(JsonCalendarStoreConfig { db_path }) => {
+        CalendarStoreConfig::Toml(TomlCalendarStoreConfig { db_path }) => {
             match fs::read_to_string(db_path) {
-                Ok(json) => serde_json::from_str::<JsonCalendarStore>(&json).unwrap(),
-                Err(_) => JsonCalendarStore::new(db_path.to_string()),
+                Ok(content) => toml::from_str::<TomlCalendarStore>(&content).unwrap(),
+                Err(_) => TomlCalendarStore::new(db_path.to_string()),
             }
         }
     }));