diff --git a/crates/format/src/lib.rs b/crates/format/src/lib.rs
index 6f345e11c..97caafdb3 100644
--- a/crates/format/src/lib.rs
+++ b/crates/format/src/lib.rs
@@ -247,6 +247,11 @@ pub fn repair(p: &mut Presentation) {
     if !(p.notes_size.width.is_finite() && p.notes_size.width > 0.0 && p.notes_size.height.is_finite() && p.notes_size.height > 0.0) {
         p.notes_size = Presentation::default().notes_size;
     }
+    // A notes page is bounded like a slide: canvas and handout drawing scale with it.
+    p.notes_size = deckcraft_model::Size::new(
+        p.notes_size.width.clamp(*SLIDE_SIDE.start(), *SLIDE_SIDE.end()),
+        p.notes_size.height.clamp(*SLIDE_SIDE.start(), *SLIDE_SIDE.end()),
+    );
     sane_numbers(p);
 }
 
diff --git a/crates/format/src/tests.rs b/crates/format/src/tests.rs
index aa692d03f..ccda612f0 100644
--- a/crates/format/src/tests.rs
+++ b/crates/format/src/tests.rs
@@ -451,6 +451,13 @@ fn degenerate_slide_sizes_are_repaired() {
     }
 }
 
+#[test]
+fn repair_bounds_the_notes_page_size() {
+    let mut p = Presentation { notes_size: deckcraft_model::Size::new(1e12, 0.01), ..Default::default() };
+    repair(&mut p);
+    assert_eq!((p.notes_size.width, p.notes_size.height), (4032.0, 72.0));
+}
+
 /// A file whose slide size is null, a string or missing a side (written by hand or by
 /// another tool; NaN is also saved as null) opens with the default size rather than failing
 /// as damaged.