diff --git a/crates/editor2/src/editor.rs b/crates/editor2/src/editor.rs
index e985ff0ee5411e25daa2c357ff1c613526663c9b..fd60564ff35649ccfb68b5aedfff1137904a7a51 100644
--- a/crates/editor2/src/editor.rs
+++ b/crates/editor2/src/editor.rs
@@ -9717,6 +9717,8 @@ pub fn diagnostic_block_renderer(diagnostic: Diagnostic, is_valid: bool) -> Rend
                     .child(HighlightedLabel::new(line.clone(), highlights.clone()))
                     .child(
                         div()
+                            .border()
+                            .border_color(gpui::red())
                             .invisible()
                             .group_hover(group_id, |style| style.visible()).child(
                         IconButton::new(copy_id.clone(), Icon::Copy)