diff --git a/crates/ui-egui/src/content_ui.rs b/crates/ui-egui/src/content_ui.rs
index 58f954a895..5e4f2975aa 100644
--- a/crates/ui-egui/src/content_ui.rs
+++ b/crates/ui-egui/src/content_ui.rs
@@ -565,10 +565,12 @@ pub(crate) fn editor(ctx: &egui::Context, view: &mut DocView, info: &DocInfo, ad
     // shortcut: lines aligned differently from each other in a box under 60 points keep the
     // editor's left edge; anchor each line on its own if such boxes turn out to matter.
     let width = r.width().max(60.0);
-    let uniform = (0..pdfcraft_engine::paragraph_align::count(&draft.text)).all(|i| draft.style.paragraph_align(i) == draft.style.align);
-    let anchor = match draft.style.align {
-        pdfcraft_engine::TextAlign::Center if uniform => 0.5,
-        pdfcraft_engine::TextAlign::Right if uniform => 1.0,
+    // The alignment every line shares, its own or the box's.
+    let first = draft.style.paragraph_align(0);
+    let shared = (1..pdfcraft_engine::paragraph_align::count(&draft.text)).all(|i| draft.style.paragraph_align(i) == first).then_some(first);
+    let anchor = match shared {
+        Some(pdfcraft_engine::TextAlign::Center) => 0.5,
+        Some(pdfcraft_engine::TextAlign::Right) => 1.0,
         _ => 0.0,
     };
     let at = r.min - egui::vec2((width - r.width()) * anchor, 0.0);
diff --git a/crates/ui-egui/tests/it/content.rs b/crates/ui-egui/tests/it/content.rs
index a4024e513e..0798abdff5 100644
--- a/crates/ui-egui/tests/it/content.rs
+++ b/crates/ui-egui/tests/it/content.rs
@@ -760,6 +760,29 @@ fn the_text_editor_aligns_a_narrow_box_to_its_own_edge() {
     assert!(inside > 20 && past == 0, "the text is drawn in its box ({inside} dark pixels in it, {past} past its right edge)");
 }
 
+/// The same when the line is right-aligned on its own while the box keeps Left: all its lines
+/// share one alignment, so the editor keeps the box's right edge for them.
+#[test]
+fn the_text_editor_aligns_a_narrow_box_whose_lines_share_an_alignment() {
+    let _gpu = gpu();
+    let mut h = harness();
+    let rect = [40.0, 195.0, 60.0, 210.0];
+    let text = pdfcraft_engine::AddedText { rect, text: "Hi".into(), aligns: vec![Some(pdfcraft_engine::TextAlign::Right)], ..Default::default() };
+    assert_eq!(text.align, pdfcraft_engine::TextAlign::Left);
+    assert!(h.state_mut().apply_edit(pdfcraft_engine::Edit::AddText { page: 0, text }));
+    assert!(h.state_mut().execute("edit.text"));
+    h.run_steps(3);
+    let point = at(&h, 50.0, 195.0);
+    click(&mut h, point);
+    assert_eq!(h.state().views[0].content.draft.as_ref().and_then(|d| d.index), Some(0), "the editor opened on the text");
+    h.run_steps(3);
+    let r = item_on_screen(&h, rect);
+    let pixels = h.render().unwrap();
+    let inside = ink(&pixels, r);
+    let past = ink(&pixels, egui::Rect::from_min_max(pos2(r.right() + 2.0, r.min.y), pos2(r.right() + 40.0, r.max.y)));
+    assert!(inside > 20 && past == 0, "the text is drawn in its box ({inside} dark pixels in it, {past} past its right edge)");
+}
+
 fn mode_tab(h: &Harness<'static, PdfCraftApp>, label: &str) -> egui::Rect {
     h.get_all_by_role_and_label(egui::accesskit::Role::Button, label).map(|n| n.rect()).find(|r| r.bottom() < 120.0).expect("a mode tab")
 }