diff --git a/docs/ARCHITEKTUR.md b/docs/ARCHITEKTUR.md
index 4b94c4c..a786be7 100644
--- a/docs/ARCHITEKTUR.md
+++ b/docs/ARCHITEKTUR.md
@@ -414,8 +414,10 @@ markiert und sortiert stattdessen serverseitig über alle Seiten
 **`VERSION`-Datei als Single Source.** `finance/VERSION` (ein Einzeiler, z.B.
 `0.4.0`) ist die einzige Versionsquelle: `app/version.py::get_version()`
 liest sie (Fallback `"0.0.0-dev"`), gespeist in den Jinja2-Footer
-(`templates.env.globals["app_version"]` in `routers/gui.py`) und
-`GET /api/version` (`main.py`). `Containerfile` kopiert `VERSION` ins Image;
+(`templates.env.globals["app_version"]` in `routers/gui.py`), als
+Cache-Busting-Parameter an allen statischen Dateien (`/static/style.css?v=…`
+usw. in `base.html`/`login.html` — ohne ihn behalten Browser alte CSS/JS
+über ein Release hinaus) und `GET /api/version` (`main.py`). `Containerfile` kopiert `VERSION` ins Image;
 `create_pod_finance.sh` liest dieselbe Datei für den Image-Tag
 (`API_IMAGE="localhost/finance-api:$(cat "$FINANCE_DIR/VERSION")"`). Ein
 Release ist somit: `VERSION` hochzählen → Image bauen → Redeploy.
diff --git a/finance/VERSION b/finance/VERSION
index 5976b2d..092a790 100644
--- a/finance/VERSION
+++ b/finance/VERSION
@@ -1 +1 @@
-0.13.0
+0.13.1
diff --git a/finance/app/templates/base.html b/finance/app/templates/base.html
index 1f0798f..0f470cd 100644
--- a/finance/app/templates/base.html
+++ b/finance/app/templates/base.html
@@ -4,10 +4,10 @@
   <meta charset="utf-8">
   <meta name="viewport" content="width=device-width, initial-scale=1">
   <title>{% block title %}Finanzberatung{% endblock %}</title>
-  <link rel="stylesheet" href="/static/style.css">
-  <script src="/static/htmx.min.js"></script>
-  <script src="/static/sort.js"></script>
-  <script src="/static/doppelzaehlung.js"></script>
+  <link rel="stylesheet" href="/static/style.css?v={{ app_version }}">
+  <script src="/static/htmx.min.js?v={{ app_version }}"></script>
+  <script src="/static/sort.js?v={{ app_version }}"></script>
+  <script src="/static/doppelzaehlung.js?v={{ app_version }}"></script>
 </head>
 <body>
   <nav>
diff --git a/finance/app/templates/login.html b/finance/app/templates/login.html
index a8e13a3..ddeca79 100644
--- a/finance/app/templates/login.html
+++ b/finance/app/templates/login.html
@@ -4,7 +4,7 @@
   <meta charset="utf-8">
   <meta name="viewport" content="width=device-width, initial-scale=1">
   <title>Anmelden – Finanzberatung</title>
-  <link rel="stylesheet" href="/static/style.css">
+  <link rel="stylesheet" href="/static/style.css?v={{ app_version }}">
 </head>
 <body>
   <h1>Finanzberatung</h1>
diff --git a/finance/tests/test_gui.py b/finance/tests/test_gui.py
index d7fe5f8..2c8dd09 100644
--- a/finance/tests/test_gui.py
+++ b/finance/tests/test_gui.py
@@ -599,7 +599,8 @@ def test_planungs_refresh_fehler_bricht_seiten_nicht(client, monkeypatch):
 def test_base_hat_doppelzaehlungs_dialog(client):
     client.post("/login", data={"username": "admin", "password": "geheim"})
     html = client.get("/").text
-    assert '<script src="/static/doppelzaehlung.js"></script>' in html
+    from app.version import get_version
+    assert f'<script src="/static/doppelzaehlung.js?v={get_version()}"></script>' in html
     assert '<dialog id="doppelzaehlung-dialog">' in html
     assert 'id="dz-abbrechen" autofocus' in html
     assert ">Trotzdem speichern</button>" in html
@@ -637,3 +638,18 @@ def test_vorschlag_formular_nutzt_json_form_post(client):
     from pathlib import Path
     src = Path("app/templates/planning.html").read_text(encoding="utf-8")
     assert re.search(r'class="inline-form" hx-ext="json-form" hx-post="/api/recurring"', src)
+
+
+def test_statische_dateien_mit_versionskennung(client):
+    # Cache-Busting: jede neue VERSION erzwingt frische CSS/JS im Browser,
+    # sonst zeigen gecachte Altstände z. B. schwarze Tortensegmente.
+    from app.version import get_version
+    v = get_version()
+    login = client.get("/login").text
+    assert f'href="/static/style.css?v={v}"' in login
+    assert re.search(r'/static/[^"?]+"', login) is None
+    client.post("/login", data={"username": "admin", "password": "geheim"})
+    html = client.get("/").text
+    for datei in ("style.css", "htmx.min.js", "sort.js", "doppelzaehlung.js"):
+        assert f'/static/{datei}?v={v}"' in html
+    assert re.search(r'/static/[^"?]+"', html) is None
diff --git a/finance/tests/test_sort_templates.py b/finance/tests/test_sort_templates.py
index ac23fd5..b9e7894 100644
--- a/finance/tests/test_sort_templates.py
+++ b/finance/tests/test_sort_templates.py
@@ -17,7 +17,8 @@ def _follow_ids(html):
 
 def test_base_bindet_sort_js_ein(client):
     _login(client)
-    assert '<script src="/static/sort.js"></script>' in client.get("/").text
+    from app.version import get_version
+    assert f'<script src="/static/sort.js?v={get_version()}"></script>' in client.get("/").text
 
 
 def test_planung_folgezeilen_markiert(client, db):