diff --git a/options/options.css b/options/options.css
index 8560c5b0..766be243 100644
--- a/options/options.css
+++ b/options/options.css
@@ -46,6 +46,10 @@ body {
   position: relative;
 }
 
+.block:nth-last-child(2) {
+  margin-bottom: 0;
+}
+
 .block:last-child {
   border-bottom: none;
   padding-bottom: 0;
diff --git a/options/options.js b/options/options.js
index 462600dc..fba0903c 100644
--- a/options/options.js
+++ b/options/options.js
@@ -6,7 +6,8 @@ setupRadioButtons();
 enforceInputRange($('#popupWidth'));
 setTimeout(splitLongTooltips);
 
-if (!FIREFOX && !OPERA) {
+// collapse #advanced block in Chrome pre-66 (classic chrome://extensions UI)
+if (!FIREFOX && !OPERA && CHROME < 3343) {
   const block = $('#advanced');
   $('h1', block).onclick = event => {
     event.preventDefault();