diff --git a/app/common/dnd-util.ts b/app/common/dnd-util.ts
index 26527933..afae0f1c 100644
--- a/app/common/dnd-util.ts
+++ b/app/common/dnd-util.ts
@@ -3,14 +3,14 @@ import * as ConfigUtil from "./config-util";
 type SettingName = "showNotification" | "silent" | "flashTaskbarOnMessage";
 
 export interface DNDSettings {
-  showNotification?: boolean;
-  silent?: boolean;
-  flashTaskbarOnMessage?: boolean;
+  showNotification: boolean;
+  silent: boolean;
+  flashTaskbarOnMessage: boolean;
 }
 
 interface Toggle {
   dnd: boolean;
-  newSettings: DNDSettings;
+  newSettings: Partial<DNDSettings>;
 }
 
 export function toggle(): Toggle {
@@ -20,9 +20,9 @@ export function toggle(): Toggle {
     dndSettingList.push("flashTaskbarOnMessage");
   }
 
-  let newSettings: DNDSettings;
+  let newSettings: Partial<DNDSettings>;
   if (dnd) {
-    const oldSettings: DNDSettings = {};
+    const oldSettings: Partial<DNDSettings> = {};
     newSettings = {};
 
     // Iterate through the dndSettingList.
diff --git a/app/common/typed-ipc.ts b/app/common/typed-ipc.ts
index 33d8097f..5da11e8b 100644
--- a/app/common/typed-ipc.ts
+++ b/app/common/typed-ipc.ts
@@ -73,7 +73,7 @@ export interface RendererMessage {
     autoHideMenubar: boolean,
     updateMenu: boolean,
   ) => void;
-  "toggle-dnd": (state: boolean, newSettings: DNDSettings) => void;
+  "toggle-dnd": (state: boolean, newSettings: Partial<DNDSettings>) => void;
   "toggle-menubar-setting": (state: boolean) => void;
   "toggle-sidebar": (show: boolean) => void;
   "toggle-sidebar-setting": (state: boolean) => void;
diff --git a/app/renderer/js/main.ts b/app/renderer/js/main.ts
index f4b29ff2..1ec24039 100644
--- a/app/renderer/js/main.ts
+++ b/app/renderer/js/main.ts
@@ -46,12 +46,12 @@ interface SettingsOptions extends DNDSettings {
   customCSS: boolean;
   lastActiveTab: number;
   dnd: boolean;
-  dndPreviousSettings: DNDSettings;
+  dndPreviousSettings: Partial<DNDSettings>;
   downloadsPath: string;
   quitOnClose: boolean;
   promptDownload: boolean;
-  dockBouncing?: boolean;
-  spellcheckerLanguages?: string[];
+  dockBouncing: boolean;
+  spellcheckerLanguages: string[];
 }
 
 type WebviewListener =
@@ -194,7 +194,7 @@ class ServerManagerView {
   // This will make sure the default settings are correctly set to either true or false
   initDefaultSettings(): void {
     // Default settings which should be respected
-    const settingOptions: SettingsOptions = {
+    const settingOptions: Partial<SettingsOptions> = {
       autoHideMenubar: false,
       trayIcon: true,
       useManualProxy: false,
@@ -226,7 +226,7 @@ class ServerManagerView {
     if (process.platform === "win32") {
       // Only available on Windows
       settingOptions.flashTaskbarOnMessage = true;
-      settingOptions.dndPreviousSettings.flashTaskbarOnMessage = true;
+      settingOptions.dndPreviousSettings!.flashTaskbarOnMessage = true;
     }
 
     if (process.platform === "darwin") {
@@ -1074,7 +1074,7 @@ class ServerManagerView {
 
     ipcRenderer.on(
       "toggle-dnd",
-      (event: Event, state: boolean, newSettings: DNDSettings) => {
+      (event: Event, state: boolean, newSettings: Partial<DNDSettings>) => {
         this.toggleDNDButton(state);
         ipcRenderer.send(
           "forward-message",
diff --git a/app/renderer/js/pages/preference/preference.ts b/app/renderer/js/pages/preference/preference.ts
index 69458feb..955e6e7d 100644
--- a/app/renderer/js/pages/preference/preference.ts
+++ b/app/renderer/js/pages/preference/preference.ts
@@ -92,7 +92,7 @@ export function initPreferenceView(): void {
 
   ipcRenderer.on(
     "toggle-dnd",
-    (_event: Event, _state: boolean, newSettings: DNDSettings) => {
+    (_event: Event, _state: boolean, newSettings: Partial<DNDSettings>) => {
       handleToggle("show-notification-option", newSettings.showNotification);
       handleToggle("silent-option", newSettings.silent);