diff --git a/frontend/main.js b/frontend/main.js
index a434cce..5574e46 100644
--- a/frontend/main.js
+++ b/frontend/main.js
@@ -61,6 +61,14 @@ async function initClient () {
   window.client = createClient(OliveTinApiService, transport)
   window.initResponse = await window.client.init({})
 
+  if (window.initResponse.enableCustomJs) {
+    const script = document.createElement('script')
+    script.src = '/custom-webui/custom.js'
+    script.async = true
+    script.id = 'olivetin-custom-js'
+    document.head.appendChild(script)
+  }
+
   const i18nSettings = createI18n({
     legacy: false,
     locale: getSelectedLanguage(),
diff --git a/frontend/resources/vue/App.vue b/frontend/resources/vue/App.vue
index 5c1fa52..5648191 100644
--- a/frontend/resources/vue/App.vue
+++ b/frontend/resources/vue/App.vue
@@ -231,6 +231,7 @@ function updateHeaderFromInit() {
     }
 
     applyStyleMods()
+    loadCustomJsIfEnabled()
 
     renderNavigation()
     applyTheme()
@@ -369,6 +370,17 @@ function applyTheme() {
     }
 }
 
+function loadCustomJsIfEnabled() {
+    if (!window.initResponse?.enableCustomJs || document.getElementById('olivetin-custom-js')) {
+        return
+    }
+    const script = document.createElement('script')
+    script.src = '/custom-webui/custom.js'
+    script.async = true
+    script.id = 'olivetin-custom-js'
+    document.head.appendChild(script)
+}
+
 function applyStyleMods() {
     if (!window.initResponse || !window.initResponse.styleMods) {
         return