diff --git a/.gitignore b/.gitignore
index b42c743..594c920 100644
--- a/.gitignore
+++ b/.gitignore
@@ -6,3 +6,4 @@ backups/
 *.log
 .claude/
 *.csv
+public/static/.asset-version
diff --git a/public/index.php b/public/index.php
index f8f0dfe..eda11df 100644
--- a/public/index.php
+++ b/public/index.php
@@ -6,6 +6,11 @@ define('BASE_DIR', dirname(__DIR__));
 
 require BASE_DIR . '/vendor/autoload.php';
 
+// Cache-Buster für statische Assets: Git-Commit-Hash aus Datei lesen
+$_assetVersionFile = BASE_DIR . '/public/static/.asset-version';
+define('ASSET_VERSION', file_exists($_assetVersionFile) ? trim(file_get_contents($_assetVersionFile)) : 'dev');
+unset($_assetVersionFile);
+
 use Steuerkram\Auth;
 use Steuerkram\Config;
 use Steuerkram\Router;
diff --git a/scripts/update.sh b/scripts/update.sh
index 5b159b6..c8a6c59 100755
--- a/scripts/update.sh
+++ b/scripts/update.sh
@@ -161,6 +161,10 @@ else
     for f in "${CHANGED_FILES[@]}"; do info "  $f"; done
 fi
 
+# Asset-Version aktualisieren (Cache-Buster für CSS/JS)
+git rev-parse --short HEAD > "$PROJECT_DIR/public/static/.asset-version"
+ok "Asset-Version gesetzt: $(cat "$PROJECT_DIR/public/static/.asset-version")"
+
 # ── Rebuild-Bedarf ermitteln ─────────────────────────────────────────────────
 NEEDS_REBUILD=false
 
diff --git a/src/Views/layout/base.php b/src/Views/layout/base.php
index e502b52..6b64eb8 100644
--- a/src/Views/layout/base.php
+++ b/src/Views/layout/base.php
@@ -4,7 +4,7 @@
     <meta charset="UTF-8">
     <meta name="viewport" content="width=device-width, initial-scale=1.0">
     <title><?= \Steuerkram\View::h($pageTitle ?? 'Steuerkram') ?> – Steuerkram</title>
-    <link rel="stylesheet" href="/static/css/app.css">
+    <link rel="stylesheet" href="/static/css/app.css?v=<?= defined('ASSET_VERSION') ? ASSET_VERSION : 'dev' ?>">
     <link rel="icon" type="image/png" href="/static/favicon/favicon-96x96.png" sizes="96x96" />
     <link rel="icon" type="image/svg+xml" href="/static/favicon/favicon.svg" />
     <link rel="shortcut icon" href="/static/favicon/favicon.ico" />
@@ -47,6 +47,6 @@
         </div>
     </div>
 </div>
-<script src="/static/js/app.js"></script>
+<script src="/static/js/app.js?v=<?= defined('ASSET_VERSION') ? ASSET_VERSION : 'dev' ?>"></script>
 </body>
 </html>
diff --git a/src/Views/login.php b/src/Views/login.php
index c5c78f4..078ca50 100644
--- a/src/Views/login.php
+++ b/src/Views/login.php
@@ -4,7 +4,7 @@
     <meta charset="UTF-8">
     <meta name="viewport" content="width=device-width, initial-scale=1.0">
     <title>Anmelden – Steuerkram</title>
-    <link rel="stylesheet" href="/static/css/app.css">
+    <link rel="stylesheet" href="/static/css/app.css?v=<?= defined('ASSET_VERSION') ? ASSET_VERSION : 'dev' ?>">
     <link rel="icon" type="image/png" href="/static/favicon/favicon-96x96.png" sizes="96x96">
     <link rel="icon" type="image/svg+xml" href="/static/favicon/favicon.svg">
     <link rel="shortcut icon" href="/static/favicon/favicon.ico">