diff --git a/src/bin/flat/tube/coords.rs b/src/bin/flat/tube/coords.rs
index cd5ba46..17fc479 100644
--- a/src/bin/flat/tube/coords.rs
+++ b/src/bin/flat/tube/coords.rs
@@ -142,6 +142,7 @@ mod tests {
 	}
 
 	fn test_flat_region(region: &impl FlatRegion, range_global: (Vec2, Vec2), range_flat: (Vec2, Vec2)) {
+		#[allow(non_upper_case_globals)]
 		const ε: f32 = 1e-3;
 		macro_rules! assert_eq_at {
 			($at: expr, $left: expr, $right: expr) => {