diff --git a/crates/maestro-tui/src/structured_pane.rs b/crates/maestro-tui/src/structured_pane.rs
index 26b7b28..ed14064 100644
--- a/crates/maestro-tui/src/structured_pane.rs
+++ b/crates/maestro-tui/src/structured_pane.rs
@@ -678,10 +678,11 @@ fn render_diff_ops(ops: &[DiffOp<'_>]) -> Vec<String> {
             for op in run.iter().take(keep_head) {
                 push_diff_op(&mut rendered, *op);
             }
-            rendered.push(format!(
-                "… {} unchanged lines …",
-                run.len() - keep_head - keep_tail
-            ));
+            let collapsed = &run[keep_head..run.len() - keep_tail];
+            rendered.push(format!("… {} unchanged lines …", collapsed.len()));
+            if collapsed.iter().any(|op| !op.line.terminated) {
+                rendered.push("\\ No newline at end of file".into());
+            }
             for op in run.iter().skip(run.len() - keep_tail) {
                 push_diff_op(&mut rendered, *op);
             }
@@ -1055,6 +1056,35 @@ mod tests {
                 "  line11",
                 "  line12",
                 "… 7 unchanged lines …",
+                "\\ No newline at end of file",
+            ]
+        );
+    }
+
+    #[test]
+    fn structured_diff_preserves_eof_marker_through_trailing_collapse() {
+        let trailing = (0..10).map(|index| format!("t{index}")).collect::<Vec<_>>();
+        let old = ["OLD".into()]
+            .into_iter()
+            .chain(trailing.iter().cloned())
+            .collect::<Vec<_>>()
+            .join("\n");
+        let new = ["NEW".into()]
+            .into_iter()
+            .chain(trailing)
+            .collect::<Vec<_>>()
+            .join("\n");
+
+        assert_eq!(
+            render_diff(Some(&old), &new, None),
+            [
+                "- OLD",
+                "+ NEW",
+                "  t0",
+                "  t1",
+                "  t2",
+                "… 7 unchanged lines …",
+                "\\ No newline at end of file",
             ]
         );
     }
diff --git a/web/src/structuredDiff.test.ts b/web/src/structuredDiff.test.ts
index 70c2ced..837f671 100644
--- a/web/src/structuredDiff.test.ts
+++ b/web/src/structuredDiff.test.ts
@@ -114,6 +114,22 @@ describe("computeDiffLines", () => {
     expect(lines.filter((l) => l.kind === "hunk")).toHaveLength(2);
   });
 
+  it("preserves the EOF marker when a long unterminated trailing run collapses", () => {
+    const trailing = Array.from({ length: 10 }, (_, i) => `t${i}`);
+    const oldText = ["OLD", ...trailing].join("\n");
+    const newText = ["NEW", ...trailing].join("\n");
+
+    expect(texts(computeDiffLines(oldText, newText))).toEqual([
+      ["del", "OLD"],
+      ["add", "NEW"],
+      ["ctx", "t0"],
+      ["ctx", "t1"],
+      ["ctx", "t2"],
+      ["hunk", "⋯ 7 unchanged lines ⋯"],
+      ["eof", "\\ No newline at end of file"],
+    ]);
+  });
+
   it("produces one hunk for the long middle run, none for the short edges", () => {
     // Edge runs (2 lines) fit within their one-sided 3-line context budget;
     // only the interior run (10 lines, budgeted 3+3=6) needs to collapse.
diff --git a/web/src/structuredDiff.ts b/web/src/structuredDiff.ts
index c7eb8b0..5654114 100644
--- a/web/src/structuredDiff.ts
+++ b/web/src/structuredDiff.ts
@@ -130,10 +130,14 @@ function hunk(ops: Op[]): DiffLine[] {
       run.forEach(push);
     } else {
       if (keepHead) run.slice(0, keepHead).forEach(push);
+      const collapsed = run.slice(keepHead, run.length - keepTail);
       out.push({
         kind: "hunk",
-        text: `⋯ ${run.length - keepHead - keepTail} unchanged lines ⋯`,
+        text: `⋯ ${collapsed.length} unchanged lines ⋯`,
       });
+      if (collapsed.some((op) => !op.line.terminated)) {
+        out.push({ kind: "eof", text: "\\ No newline at end of file" });
+      }
       if (keepTail) run.slice(run.length - keepTail).forEach(push);
     }
     i = j;