diff --git a/src/app/ui.rs b/src/app/ui.rs
index 7975863..0e5fb06 100644
--- a/src/app/ui.rs
+++ b/src/app/ui.rs
@@ -546,13 +546,18 @@ impl App {
                     if self.config.show_preview {
                         // Editor + read-only source-ish preview side by side.
                         let full = ui.available_size();
+                        // Both columns need an explicit top-down layout: a child
+                        // `Ui` inherits its parent's, and inside `horizontal_top`
+                        // that is left-to-right, which would run every paragraph
+                        // of the preview onto one line.
+                        let down = egui::Layout::top_down(egui::Align::Min);
                         ui.horizontal_top(|ui| {
                             let col_w = full.x / 2.0 - 6.0;
-                            ui.allocate_ui(egui::vec2(col_w, full.y), |ui| {
+                            ui.allocate_ui_with_layout(egui::vec2(col_w, full.y), down, |ui| {
                                 self.editor(ui);
                             });
                             ui.separator();
-                            ui.allocate_ui(egui::vec2(col_w, full.y), |ui| {
+                            ui.allocate_ui_with_layout(egui::vec2(col_w, full.y), down, |ui| {
                                 egui::ScrollArea::vertical()
                                     .id_salt("preview")
                                     .auto_shrink([false, false])