diff --git a/crates/doc/src/lib.rs b/crates/doc/src/lib.rs
index 1d1b5452b..6ad1973c9 100644
--- a/crates/doc/src/lib.rs
+++ b/crates/doc/src/lib.rs
@@ -1373,7 +1373,8 @@ impl Document {
     /// inside or on its left or top edge, else the first (the last) that holds it by
     /// [`artboard_holds`]: on its right or bottom edge, or within a millionth of a point outside an
     /// edge. On an edge two artboards share, the artboard to the right of it or below it holds the
-    /// point.
+    /// point, except at the end of the edge that lies on that artboard's bottom or right edge, such
+    /// as the point where both artboards' bottom edges meet; there the first (the last) holds it.
     pub fn artboard_holding(&self, p: Point, topmost: bool) -> Option<usize> {
         let pick = |on: &dyn Fn(Rect) -> bool| {
             let on = |i: &usize| self.artboards.get(*i).is_some_and(|a| on(a.rect));
@@ -1881,9 +1882,13 @@ mod tests {
         assert_eq!(held(&d, 200.001, 50.0), (None, None));
         assert_eq!(held(&d, 50.0, 200.001), (None, None));
         // On an edge two artboards share, the artboard to the right of it or below it holds the
-        // point, in either list order.
+        // point, in either list order, except at the end of the edge that lies on that artboard's
+        // bottom or right edge.
         assert_eq!(held(&d, 100.0, 50.0), (Some(1), Some(1)));
         assert_eq!(held(&d, 50.0, 100.0), (Some(2), Some(2)));
+        // The bottom edges of artboards 0 and 1 meet at (100, 100), which is also artboard 2's top
+        // right corner: the first holds the point, or the last when `topmost`.
+        assert_eq!(held(&d, 100.0, 100.0), (Some(2), Some(0)), "shared corner");
         d.artboards.swap(0, 1);
         assert_eq!(held(&d, 100.0, 50.0), (Some(0), Some(0)));
         // Where two artboards overlap, the topmost holds the point, or the first one when not
diff --git a/crates/engine/src/tests_newdoc.rs b/crates/engine/src/tests_newdoc.rs
index 82ca009d6..bada2ebba 100644
--- a/crates/engine/src/tests_newdoc.rs
+++ b/crates/engine/src/tests_newdoc.rs
@@ -330,8 +330,8 @@ fn rearrange_lays_out_by_layout_and_order() {
     }
 }
 
-/// Art centered on an artboard's right or bottom edge moves with that artboard, and art on the edge
-/// two artboards share moves with the artboard to the right of it.
+/// Art centered on an artboard's right or bottom edge moves with that artboard, and art centered on
+/// the edge two artboards share, away from its ends, moves with the artboard to the right of it.
 #[test]
 fn rearrange_moves_art_centered_on_an_artboard_edge() {
     let mut s = new_doc(json!({"width": 100, "height": 50, "artboards": 2, "artboardLayout": {"layout": "row", "spacing": 0}}));
diff --git a/crates/engine/src/tests_textimport.rs b/crates/engine/src/tests_textimport.rs
index 780983750..244b1d3d5 100644
--- a/crates/engine/src/tests_textimport.rs
+++ b/crates/engine/src/tests_textimport.rs
@@ -52,8 +52,8 @@ fn crlf_with_returns_removed_places_one_paragraph_per_block_as_area_type() {
 }
 
 /// Placed at a point on an artboard's right or bottom edge, the frame takes that artboard's size less
-/// a 36 pt margin on each side; on the edge two artboards share, it takes the size of the artboard to
-/// the right of it.
+/// a 36 pt margin on each side; on the edge two artboards share, away from its ends, it takes the
+/// size of the artboard to the right of it.
 #[test]
 fn type_placed_on_an_artboard_edge_takes_that_artboards_frame() {
     let mut s = session();
diff --git a/crates/svg/tests/css_rules.rs b/crates/svg/tests/css_rules.rs
index 5ac99c596..036f1bd91 100644
--- a/crates/svg/tests/css_rules.rs
+++ b/crates/svg/tests/css_rules.rs
@@ -71,7 +71,8 @@ fn rectangle_gives_background_border_and_radius() {
 }
 
 /// An object centered on an artboard's right or bottom edge is positioned from that artboard's
-/// top-left corner; on the edge two artboards share, from the one to the right of it.
+/// top-left corner; on the edge two artboards share, away from its ends, from the one to the right
+/// of it.
 #[test]
 fn position_is_from_the_artboard_whose_edge_holds_the_center() {
     let mut d = doc();