--- a/devtools/client/memory/components/dominator-tree.js
+++ b/devtools/client/memory/components/dominator-tree.js
@@ -88,16 +88,17 @@ const DominatorTreeSiblingLink = createF
       dom.span({ className: "heap-tree-item-field heap-tree-item-bytes" }),
       dom.span(
         {
           className: "heap-tree-item-field heap-tree-item-name",
           style: { marginInlineStart: depth * TREE_ROW_HEIGHT }
         },
         dom.a(
           {
+            className: "load-more",
             onClick: () => onLoadMoreSiblings(item)
           },
           L10N.getStr("tree-item.load-more")
         )
       )
     );
   }
 }));

--- a/devtools/client/themes/memory.css
+++ b/devtools/client/themes/memory.css
@@ -539,16 +539,25 @@ html, body, #app, #memory-tool {
 
 .tree-map-container {
   width: 100%;
   height: 100%;
   position: relative;
   overflow: hidden;
 }
 
+.load-more {
+  cursor: pointer;
+  font-weight: bold;
+}
+
+.load-more:hover {
+  text-decoration: underline;
+}
+
 /**
  * Heap tree errors.
  */
 
 .error::before {
   content: "";
   display: inline-block;
   width: 12px;