diff --git a/petri/src/lib.rs b/petri/src/lib.rs
index bb397c1..2bec3e1 100644
--- a/petri/src/lib.rs
+++ b/petri/src/lib.rs
@@ -45,7 +45,7 @@ pub struct CellData {
 	pub color: [u8; 3],
 }
 
-#[derive(Debug, Default)]
+#[derive(Debug)]
 struct Chunk {
 	pub contents: Box<[[Cell; CHUNK_SIZE]; CHUNK_SIZE]>,
 }
@@ -338,8 +338,8 @@ impl Rule {
 	}
 }
 
-impl Chunk {
-	fn new() -> Self {
+impl Default for Chunk {
+	fn default() -> Self {
 		Self {
 			contents: vec![[Cell(0); CHUNK_SIZE]; CHUNK_SIZE]
 				.into_boxed_slice()
@@ -347,7 +347,9 @@ impl Chunk {
 				.unwrap(),
 		}
 	}
+}
 
+impl Chunk {
 	fn fill(&mut self, cell: Cell) {
 		self.contents.fill([cell; CHUNK_SIZE]);
 	}
@@ -416,7 +418,7 @@ impl Dish {
 
 		let mut new = Self {
 			world: World {
-				chunk: Chunk::new().with_random_ones(),
+				chunk: Chunk::default().with_random_ones(),
 			},
 			rules: default_rules,
 			types: vec![
diff --git a/uscope/src/main.rs b/uscope/src/main.rs
index aae6a26..5154f04 100644
--- a/uscope/src/main.rs
+++ b/uscope/src/main.rs
@@ -92,8 +92,11 @@ impl eframe::App for UScope {
 			.min_width(100.)
 			.show(ctx, |ui| {
 				ui.heading("Simulation");
-				ui.label("speed");
-				ui.add(Slider::new(&mut self.speed, 0..=500).clamp_to_range(false));
+				ui.add(
+					Slider::new(&mut self.speed, 0..=500)
+						.clamp_to_range(false)
+						.text("speed"),
+				);
 				ui.label(format!("sim time: {sim_time:?}"));
 				let avg_sim_time =
 					self.sim_times.iter().sum::<Duration>() / self.sim_times.len() as u32;
@@ -207,7 +210,9 @@ impl eframe::App for UScope {
 				});
 			});
 		CentralPanel::default().show(ctx, |ui| {
-			let bounds = ui.available_rect_before_wrap();
+			let mut bounds = ui.available_rect_before_wrap();
+			bounds.min = bounds.min.floor();
+			bounds.max = bounds.max.floor();
 			let painter = ui.painter_at(bounds);
 			paint_world(painter, &self.dish, self.show_grid);