diff --git a/main.js b/main.js
index e071a85..b44d4d9 100644
--- a/main.js
+++ b/main.js
@@ -26,7 +26,7 @@ const map = new Map({
 for (let category of layerCategories) {
   const catDiv = document.createElement("div");
   catDiv.innerHTML = `
-    <details open>
+    <details ${category.layers.filter(l => l.enabled).length > 0 ? "open" : ""}>
     <summary>${category.name}</summary>
     <ul></ul>
     </details>