diff --git a/src/client/store.ts b/src/client/store.ts
index 29709096ee..7a9d09d2a5 100644
--- a/src/client/store.ts
+++ b/src/client/store.ts
@@ -35,7 +35,7 @@ const defaultDeviceSettings = {
 	accounts: [],
 	recentEmojis: [],
 	themes: [],
-	theme: 'light',
+	theme: '4eea646f-7afa-4645-83e9-83af0333cd37',
 	animation: true,
 	animatedMfm: true,
 	imageNewTab: false,
diff --git a/src/client/theme.ts b/src/client/theme.ts
index 576096cf70..a34f2b5c34 100644
--- a/src/client/theme.ts
+++ b/src/client/theme.ts
@@ -13,8 +13,8 @@ export const lightTheme: Theme = require('./themes/_light.json5');
 export const darkTheme: Theme = require('./themes/_dark.json5');
 
 export const builtinThemes = [
-	lightTheme,
-	darkTheme,
+	require('./themes/white.json5'),
+	require('./themes/black.json5'),
 	require('./themes/lavender.json5'),
 	require('./themes/halloween.json5'),
 	require('./themes/garden.json5'),
diff --git a/src/client/themes/black.json5 b/src/client/themes/black.json5
new file mode 100644
index 0000000000..75ddaafead
--- /dev/null
+++ b/src/client/themes/black.json5
@@ -0,0 +1,13 @@
+{
+	id: '8c539dc1-0fab-4d47-9194-39c508e9bfe1',
+
+	name: 'Black',
+	author: 'syuilo',
+	desc: '',
+
+	base: 'dark',
+
+	props: {
+		divider: '#2b2b2b',
+	},
+}
diff --git a/src/client/themes/white.json5 b/src/client/themes/white.json5
new file mode 100644
index 0000000000..845cdcf39c
--- /dev/null
+++ b/src/client/themes/white.json5
@@ -0,0 +1,13 @@
+{
+	id: '4eea646f-7afa-4645-83e9-83af0333cd37',
+
+	name: 'White',
+	author: 'syuilo',
+	desc: '',
+
+	base: 'light',
+
+	props: {
+		messageBg: '#dedede',
+	},
+}