diff --git a/crates/doc/src/sheet.rs b/crates/doc/src/sheet.rs
index b8dcc0ec..fa1af19b 100644
--- a/crates/doc/src/sheet.rs
+++ b/crates/doc/src/sheet.rs
@@ -5597,7 +5597,7 @@ mod tests {
                         assert!((s.base.area() - base).abs() < tol, "{what}: {} vs {base}", s.base.area());
                         assert!((flat_area(&s) - (base + len * (ba + panel))).abs() < 1e-6, "{what}: {}", flat_area(&s));
                         // (A sliver 0.0001 wide is below the flat pattern's shortest edge.)
-                        if hair < 0.0 || hair > 1e-3 {
+                        if !(0.0..=1e-3).contains(&hair) {
                             holds_the_flat_material(&s, &what);
                         } else {
                             let b = s.solid().unwrap_or_else(|e| panic!("{what}: no solid: {e}"));
diff --git a/crates/kernel/src/prism_local.rs b/crates/kernel/src/prism_local.rs
index 4bbb4d44..8456d453 100644
--- a/crates/kernel/src/prism_local.rs
+++ b/crates/kernel/src/prism_local.rs
@@ -239,7 +239,8 @@ fn survey(body: &Body, d: Vec3, tol: f64, mesh_tol: f64, axes: [Vec3; 3]) -> Opt
                     let o = p.origin();
                     flat.push((n, n.dot(Vec3::new(o.x, o.y, o.z))));
                     let along = n.dot(d).abs();
-                    !(along > 1.0 - 1e-9 || along < 1e-9)
+                    // NaN counts as inside, as the comparisons it replaces did.
+                    along.is_nan() || (1e-9..=1.0 - 1e-9).contains(&along)
                 }
                 _ => !crate::prism::wall_along(&surface, d, tol, &mut work),
             }
diff --git a/crates/ui-egui/src/navigation.rs b/crates/ui-egui/src/navigation.rs
index 7f401cf9..aed11634 100644
--- a/crates/ui-egui/src/navigation.rs
+++ b/crates/ui-egui/src/navigation.rs
@@ -165,8 +165,7 @@ pub(crate) fn modifier_motion(
         && app.viewport.boxsel.is_none()
         && !(picking && hover.is_some_and(|p| app.viewport.rect.is_some_and(|rect| crate::canvas::owns_pointer(app, &projection(app, rect), p))))
         && !hover.is_some_and(|p| app.viewport.layout.as_ref().is_some_and(|l| l.navigation.contains(p)));
-    let next =
-        hover.filter(|p| owns && p.is_finite()).and_then(|p| crate::prefs::nav_preset(&app.preferences.nav).motion_mode(mods).map(|mode| (mode, p)));
+    let next = crate::prefs::nav_preset(&app.preferences.nav).motion_mode(mods).zip(hover.filter(|p| owns && p.is_finite()));
     let previous = app.viewport.modifier_nav;
     if previous.map(|(m, _)| m) != next.map(|(m, _)| m) {
         app.viewport.orbit_pivot = None;