diff --git a/packages/core/src/browser/tree/tree-widget.tsx b/packages/core/src/browser/tree/tree-widget.tsx
index 58c327ac3c7fb..49e285ee01f22 100644
--- a/packages/core/src/browser/tree/tree-widget.tsx
+++ b/packages/core/src/browser/tree/tree-widget.tsx
@@ -411,7 +411,7 @@ export class TreeWidget extends ReactWidget implements StatefulWidget {
         return <div
             data-node-id={node.id}
             className={className}
-            style={{ paddingLeft: '4px' }}
+            style={{ paddingLeft: '4px', paddingRight: '4px' }}
             onClick={this.toggle}>
         </div>;
     }