diff --git a/config.ini b/config.ini
index 95ff810..ac457af 100644
--- a/config.ini
+++ b/config.ini
@@ -1,7 +1,7 @@
 [EMLy]
 SDK_DECODER_SEMVER          = 1.3.2
 SDK_DECODER_RELEASE_CHANNEL = stable
-GUI_SEMVER                  = 1.5.2
+GUI_SEMVER                  = 1.5.3
 GUI_RELEASE_CHANNEL         = beta
 LANGUAGE                    = it
 UPDATE_CHECK_ENABLED        = false
diff --git a/frontend/src/app.html b/frontend/src/app.html
index 08986d3..f10b968 100644
--- a/frontend/src/app.html
+++ b/frontend/src/app.html
@@ -14,7 +14,7 @@
 				try {
 					const key = "emly_theme";
 					const stored = localStorage.getItem(key);
-					const theme = stored === "light" || stored === "dark" ? stored : "light";
+					const theme = stored === "light" || stored === "dark" ? stored : "dark";
 					document.documentElement.classList.toggle("dark", theme === "dark");
 				} catch {
 					// If storage is blocked, default to light.
diff --git a/frontend/src/lib/stores/settings.svelte.ts b/frontend/src/lib/stores/settings.svelte.ts
index 2535818..bba82ca 100644
--- a/frontend/src/lib/stores/settings.svelte.ts
+++ b/frontend/src/lib/stores/settings.svelte.ts
@@ -57,6 +57,9 @@ class SettingsStore {
             this.settings.theme = storedTheme;
         }
         
+        // Sync useDarkEmailViewer with theme
+        this.settings.useDarkEmailViewer = this.settings.theme === "dark";
+        
         // Apply the theme
         applyTheme(this.settings.theme);
 
diff --git a/frontend/src/routes/(app)/settings/+page.svelte b/frontend/src/routes/(app)/settings/+page.svelte
index 331c632..60cb7c6 100644
--- a/frontend/src/routes/(app)/settings/+page.svelte
+++ b/frontend/src/routes/(app)/settings/+page.svelte
@@ -211,6 +211,16 @@
     })();
   });
 
+  // Sync theme with email viewer dark mode
+  let previousTheme = $state<string | undefined>(undefined);
+  $effect(() => {
+    if (!browser) return;
+    if (previousTheme !== undefined && form.theme !== previousTheme) {
+      form.useDarkEmailViewer = form.theme === "dark";
+    }
+    previousTheme = form.theme;
+  });
+
   async function exportSettings() {
     try {
       const settingsJSON = JSON.stringify(form, null, 2);
diff --git a/installer/installer.iss b/installer/installer.iss
index 0b2a027..8e61fb7 100644
--- a/installer/installer.iss
+++ b/installer/installer.iss
@@ -1,6 +1,6 @@
 #define ApplicationName 'EMLy'
 #define ApplicationVersion GetVersionNumbersString('EMLy.exe')
-#define ApplicationVersion '1.5.2'
+#define ApplicationVersion '1.5.3_beta'
 
 [Languages]
 Name: "english"; MessagesFile: "compiler:Default.isl"