diff --git a/src/app.rs b/src/app.rs
index eaafa91..d565458 100644
--- a/src/app.rs
+++ b/src/app.rs
@@ -1,9 +1,10 @@
+use std::sync::Arc;
 use crate::data::Id;
 use crate::data::entities::DeckSettings;
 use crate::data::entities::{WordData, WordGroup};
 use crate::data_provider::decks::load_sets;
 use crate::data_provider::settings::get_setting;
-use crate::data_provider::sqlite::default_connection;
+use crate::data_provider::sqlite::{SqliteConnection};
 use crate::data_provider::words::{load_word_groups, load_words};
 use crate::navigation::RootMessage::Keyboard;
 use crate::navigation::{AppSettings, RootMessage, ScreenState};
@@ -15,6 +16,7 @@ use iced_core::window::Position;
 use iced_core::window::settings::PlatformSpecific;
 use iced_core::{Font, Size, Theme};
 use log::info;
+use parking_lot::RwLock;
 use rusqlite::Connection;
 pub const USER_FONT: Font = Font::with_name("Noto Sans JP");
 
@@ -57,12 +59,13 @@ fn subscription(_state: &ScreenState) -> Subscription<RootMessage> {
     keyboard::listen().map(Keyboard)
 }
 
+#[derive(Clone)]
 pub struct AppState {
     pub dictionary: Vec<WordData>,
     pub decks: Vec<DeckSettings>,
     pub word_groups: Vec<WordGroup>,
-    pub connection: Connection,
-    pub sync_data: AppSettings,
+    pub connection: Arc<RwLock<SqliteConnection>>,
+    pub sync_data: Arc<RwLock<AppSettings>>,
     pub activity: HashMap<Id, Vec<(NaiveDate, u32)>>,
 }
 
@@ -78,26 +81,27 @@ impl AppState {
             dictionary: vec![],
             decks: vec![],
             word_groups: vec![],
-            connection: default_connection(),
-            sync_data: AppSettings {
+            connection: Arc::new(RwLock::new(Default::default())),
+            sync_data: Arc::new(RwLock::new(AppSettings {
                 key: None,
                 auto_web_fetch: false,
-            },
+            })),
             activity: Default::default(),
         }
     }
 }
 
 pub fn fill_state(state: &mut AppState) {
-    let list = load_words(&state.connection);
-    let sets = load_sets(&state.connection);
-    let groups = load_word_groups(&state.connection);
-    let setting = load_settings(&state.connection);
+    let connection = state.connection.read();
+    let list = load_words(&connection);
+    let sets = load_sets(&connection);
+    let groups = load_word_groups(&connection);
+    let setting = load_settings(&connection);
 
     state.dictionary = list.unwrap_or_default();
     state.decks = sets.unwrap_or_default();
     state.word_groups = groups.unwrap_or_default();
-    state.sync_data = setting
+    state.sync_data = Arc::new(RwLock::new(setting))
 }
 
 fn load_settings(connection: &Connection) -> AppSettings {
diff --git a/src/core/deck.rs b/src/core/deck.rs
index b09e41c..d5aca96 100644
--- a/src/core/deck.rs
+++ b/src/core/deck.rs
@@ -9,15 +9,13 @@ use crate::data_provider::card_states::{load_stats_of_deck, update_stat_score};
 use crate::data_provider::history::push_note;
 use crate::notification::{MaybeError, NotificationData};
 use chrono::Utc;
-use parking_lot::Mutex;
-use std::sync::Arc;
 
 #[derive(Clone)]
 pub struct DeckData {
     pub(crate) words: Vec<WordData>,
     pub(crate) set: Vec<CardState>,
     current_word_index: Option<usize>,
-    state: Arc<Mutex<AppState>>,
+    state: AppState,
     order_module: OrderModule,
     open_mode: OrderMode,
     settings: DeckSettings,
@@ -25,21 +23,20 @@ pub struct DeckData {
 impl DeckData {
     pub fn new(
         settings: &DeckSettings,
-        state: Arc<Mutex<AppState>>,
+        state: AppState,
     ) -> Result<Self, NotificationData> {
         let state_for = state.clone();
-        let state_locked = state.lock();
 
-        let stats = load_stats_of_deck(settings, &state_locked.connection)?;
+        let stats = load_stats_of_deck(settings, &state.connection.read())?;
         let words = stats
             .iter()
             .map(|stat| {
-                state_locked
+                state
                     .dictionary
                     .binary_search_by_key(&stat.word_id, |w| w.id)
                     .expect("No word found in dictionary")
             })
-            .map(|index| &state_locked.dictionary[index])
+            .map(|index| &state.dictionary[index])
             .cloned()
             .collect();
 
@@ -117,7 +114,7 @@ impl DeckData {
                     OrderMode::FullRandom => RandomSRS(RandomSRSModule::new()),
                 }
             }
-            update_stat_score(word, &self.state.lock().connection)?;
+            update_stat_score(word, &self.state.connection.read())?;
             let _ = push_note(
                 self.settings.id,
                 HistoryItem {
diff --git a/src/data_provider/sqlite.rs b/src/data_provider/sqlite.rs
index 85821a7..2021209 100644
--- a/src/data_provider/sqlite.rs
+++ b/src/data_provider/sqlite.rs
@@ -1,5 +1,6 @@
 use crate::fs::*;
 use rusqlite::Connection;
+use std::ops::{Deref, DerefMut};
 
 pub fn create_db() {
     let db_file = db_path();
@@ -84,3 +85,29 @@ pub fn default_connection() -> Connection {
         .expect("Failed to set PRAGMA");
     connection
 }
+
+pub struct SqliteConnection(Option<Connection>);
+impl Deref for SqliteConnection {
+    type Target = Connection;
+    fn deref(&self) -> &Self::Target {
+        self.0.as_ref().unwrap()
+    }
+}
+
+impl DerefMut for SqliteConnection {
+    fn deref_mut(&mut self) -> &mut Self::Target {
+        self.0.as_mut().unwrap()
+    }
+}
+
+impl Default for SqliteConnection {
+    fn default() -> Self {
+        SqliteConnection(Some(default_connection()))
+    }
+}
+
+impl SqliteConnection {
+    pub fn finish(&mut self) {
+        self.0 = None;
+    }
+}
diff --git a/src/navigation.rs b/src/navigation.rs
index ecd87f8..acd7636 100644
--- a/src/navigation.rs
+++ b/src/navigation.rs
@@ -1,7 +1,7 @@
 use crate::app::{AppState, fill_state};
 use crate::data::Id;
 use crate::data_provider::history::get_history_of_set;
-use crate::data_provider::sqlite::{create_db, default_connection};
+use crate::data_provider::sqlite::{create_db, default_connection, SqliteConnection};
 use crate::data_provider::web_api::{
     get_local_version, get_web_version, load_data, set_local_version,
 };
@@ -47,7 +47,6 @@ impl Default for ScreenState {
     fn default() -> Self {
         let mut state = AppState::new();
         fill_state(&mut state);
-        let state = Arc::new(Mutex::new(state));
         ScreenState {
             stack: vec![Selector(SelectorState::new(state.clone()))],
             app_state: state.clone(),
@@ -99,7 +98,7 @@ pub enum Page {
 
 pub struct ScreenState {
     stack: Vec<Page>,
-    app_state: Arc<Mutex<AppState>>,
+    app_state: AppState,
     notification_manager: NotificationManager,
 }
 
@@ -114,9 +113,9 @@ impl ScreenState {
         });
 
         let mut final_task = reading_additional_task;
-        let state_guard = state.app_state.lock();
-        if state_guard.sync_data.auto_web_fetch
-            && let Some(key) = state_guard.sync_data.key.clone()
+        let state_guard = &state.app_state;
+        if state_guard.sync_data.read().auto_web_fetch
+            && let Some(key) = state_guard.sync_data.read().key.clone()
         {
             final_task = Task::batch([
                 final_task,
@@ -133,7 +132,6 @@ impl ScreenState {
             ]);
         }
 
-        drop(state_guard);
         info!("Boot finished");
         (state, final_task)
     }
@@ -192,15 +190,15 @@ impl ScreenState {
         }
 
         if let DataLoaded(data) = message {
-            self.app_state.lock().activity = data;
+            self.app_state.activity = data;
             return Task::none();
         }
 
         if let UpdateData = message {
             info!("Loading data");
-            let mut state = self.app_state.lock();
+            let state = &mut self.app_state;
             if cfg!(windows) {
-                state.connection = Connection::open_in_memory().unwrap();
+                state.connection.write().finish();
             }
             let db_file = db_path();
             let temp_db_file = temp_db_path();
@@ -208,8 +206,8 @@ impl ScreenState {
                 return push_error_task!(PermissionDenied);
             }
 
-            state.connection = default_connection();
-            fill_state(&mut state);
+            state.connection = Default::default();
+            fill_state(state);
             return Task::none();
         }
 
diff --git a/src/pages/dictionary.rs b/src/pages/dictionary.rs
index b800564..16bd9f3 100644
--- a/src/pages/dictionary.rs
+++ b/src/pages/dictionary.rs
@@ -30,7 +30,7 @@ use std::time::{Duration, Instant};
 
 #[derive(Clone)]
 pub struct DictionaryState {
-    state: Arc<Mutex<AppState>>,
+    state: AppState,
     include_map: Vec<bool>,
     tag_map: HashMap<String, bool>,
     reverse: bool,
@@ -300,7 +300,7 @@ impl NavigatedPage<DictionaryMessage> for DictionaryState {
 }
 
 impl DictionaryState {
-    pub fn new(state: Arc<Mutex<AppState>>) -> Self {
+    pub fn new(state: AppState) -> Self {
         let len = state.lock().dictionary.len();
 
         let mut result = DictionaryState {
diff --git a/src/pages/history.rs b/src/pages/history.rs
index 4cc0558..3770c21 100644
--- a/src/pages/history.rs
+++ b/src/pages/history.rs
@@ -48,7 +48,7 @@ impl NavigatedPage<HistoryMessage> for HistoryState {
 }
 
 impl HistoryState {
-    pub fn new(id: crate::data::Id, state: Arc<Mutex<AppState>>) -> Self {
+    pub fn new(id: crate::data::Id, state: AppState) -> Self {
         let state = state.lock();
         let history = get_history_of_set(id).unwrap_or_default();
         let words = history
diff --git a/src/pages/import.rs b/src/pages/import.rs
index 5a4de5d..1c18ab5 100644
--- a/src/pages/import.rs
+++ b/src/pages/import.rs
@@ -34,7 +34,7 @@ const DEFAULT_FIELDS: [&str; 6] = ["key", "value", "tags", "reading", "context",
 
 #[derive(Clone)]
 pub struct ImportState {
-    state: Arc<Mutex<AppState>>,
+    state: AppState,
     path: Option<PathBuf>,
     import_data: Option<ImportData>,
     selected_index: usize,
@@ -318,7 +318,7 @@ impl ImportState {
 }
 
 impl ImportState {
-    pub fn new(state: Arc<Mutex<AppState>>) -> ImportState {
+    pub fn new(state: AppState) -> ImportState {
         ImportState {
             state,
             path: None,
diff --git a/src/pages/repetition.rs b/src/pages/repetition.rs
index cbf5d91..e40e5f9 100644
--- a/src/pages/repetition.rs
+++ b/src/pages/repetition.rs
@@ -22,7 +22,7 @@ use std::sync::Arc;
 use tokio::task::spawn_blocking;
 
 pub struct RepetitionState {
-    state: Arc<Mutex<AppState>>,
+    state: AppState,
     pub settings: DeckSettings,
     pub set: DeckData,
     current_word: WordData,
@@ -104,7 +104,7 @@ impl NavigatedPage<RepetitionMessage> for RepetitionState {
 impl RepetitionState {
     pub(crate) fn new(
         set: DeckSettings,
-        state: Arc<Mutex<AppState>>,
+        state: AppState,
     ) -> Result<RepetitionState, NotificationData> {
         let mut card_set = DeckData::new(&set, state.clone())?;
         let (word, stat) = card_set.next();
diff --git a/src/pages/repetition_settings.rs b/src/pages/repetition_settings.rs
index cf801bb..a48cca0 100644
--- a/src/pages/repetition_settings.rs
+++ b/src/pages/repetition_settings.rs
@@ -21,14 +21,14 @@ use std::time::Duration;
 pub struct RepetitionSettingsState {
     set: DeckSettings,
     index: usize,
-    state: Arc<Mutex<AppState>>,
+    state: AppState,
     real_delete: bool,
     correct_filter: bool,
     filter_changed: bool,
 }
 
 impl RepetitionSettingsState {
-    pub(crate) fn new(index: usize, state: Arc<Mutex<AppState>>) -> RepetitionSettingsState {
+    pub(crate) fn new(index: usize, state: AppState) -> RepetitionSettingsState {
         let set;
         {
             let local_state = state.lock();
diff --git a/src/pages/repetitions.rs b/src/pages/repetitions.rs
index 38f44d2..7179ca7 100644
--- a/src/pages/repetitions.rs
+++ b/src/pages/repetitions.rs
@@ -36,7 +36,7 @@ pub struct RepetitionsState {
     word_id_index_map: HashMap<Id, usize>,
     selected_deck_index: Option<usize>,
     decks: Vec<DeckViewData>,
-    state: Arc<Mutex<AppState>>,
+    state: AppState,
 }
 
 impl NavigatedPage<RepetitionsMessage> for RepetitionsState {
@@ -257,7 +257,7 @@ impl NavigatedPage<RepetitionsMessage> for RepetitionsState {
 }
 
 impl RepetitionsState {
-    pub(crate) fn new(state: Arc<Mutex<AppState>>) -> RepetitionsState {
+    pub(crate) fn new(state: AppState) -> RepetitionsState {
         let state_ = state.lock();
         let mut map = HashMap::with_capacity(state_.dictionary.len());
 
diff --git a/src/pages/selector.rs b/src/pages/selector.rs
index f641efa..b8d1cca 100644
--- a/src/pages/selector.rs
+++ b/src/pages/selector.rs
@@ -22,7 +22,7 @@ use std::sync::Arc;
 pub struct SelectorState {
     pub set: KanaSet,
     is_writing: bool,
-    state: Arc<Mutex<AppState>>,
+    state: AppState,
 }
 
 #[derive(Debug, Clone)]
@@ -114,7 +114,7 @@ impl NavigatedPage<SelectorMessage> for SelectorState {
 }
 
 impl SelectorState {
-    pub fn new(state: Arc<Mutex<AppState>>) -> Self {
+    pub fn new(state: AppState) -> Self {
         Self {
             set: Default::default(),
             is_writing: false,
diff --git a/src/pages/sync.rs b/src/pages/sync.rs
index e9f7900..d5cf083 100644
--- a/src/pages/sync.rs
+++ b/src/pages/sync.rs
@@ -34,7 +34,7 @@ pub enum SyncMessage {
 }
 #[derive(Clone)]
 pub struct SyncState {
-    state: Arc<Mutex<AppState>>,
+    state: AppState,
     auto_fetch: bool,
     frozen: bool,
     progress: f32,
@@ -177,7 +177,7 @@ impl NavigatedPage<SyncMessage> for SyncState {
 }
 
 impl SyncState {
-    pub fn new(state: Arc<Mutex<AppState>>) -> SyncState {
+    pub fn new(state: AppState) -> SyncState {
         let auto_fetch;
         {
             auto_fetch = state.lock().sync_data.auto_web_fetch;
diff --git a/src/pages/word.rs b/src/pages/word.rs
index fa95d58..3ff5300 100644
--- a/src/pages/word.rs
+++ b/src/pages/word.rs
@@ -15,7 +15,7 @@ use std::sync::Arc;
 
 #[derive(Clone)]
 pub struct WordState {
-    state: Arc<Mutex<AppState>>,
+    state: AppState,
     index: usize,
     word: WordData,
 }
@@ -136,7 +136,7 @@ impl NavigatedPage<WordMessage> for WordState {
 }
 
 impl WordState {
-    pub(crate) fn new(word: WordData, index: usize, state: Arc<Mutex<AppState>>) -> WordState {
+    pub(crate) fn new(word: WordData, index: usize, state: AppState) -> WordState {
         WordState { state, index, word }
     }
 }