diff --git a/core/editor/src/tools/ellipse.rs b/core/editor/src/tools/ellipse.rs
index 795f06c28..52fcd0e3a 100644
--- a/core/editor/src/tools/ellipse.rs
+++ b/core/editor/src/tools/ellipse.rs
@@ -135,10 +135,14 @@ fn make_operation(data: &EllipseToolData, tool_data: &DocumentToolData) -> Opera
 	let x1 = data.drag_current.x as f64;
 	let y1 = data.drag_current.y as f64;
 
-	let (cx, cy, r_scale) = if data.center_around_cursor { (x0, y0, 1.0) } else { ((x0 + x1) * 0.5, (y0 + y1) * 0.5, 0.5) };
-
 	if data.constrain_to_circle {
-		let r = f64::max((x1 - x0).abs(), (y1 - y0).abs()) * r_scale;
+		let (cx, cy, r) = if data.center_around_cursor {
+			(x0, y0, f64::hypot(x1 - x0, y1 - y0))
+		} else {
+			let diameter = f64::max((x1 - x0).abs(), (y1 - y0).abs());
+			let (x2, y2) = (x0 + (x1 - x0).signum() * diameter, y0 + (y1 - y0).signum() * diameter);
+			((x0 + x2) * 0.5, (y0 + y2) * 0.5, diameter * 0.5)
+		};
 		Operation::AddCircle {
 			path: vec![],
 			insert_index: -1,
@@ -148,6 +152,7 @@ fn make_operation(data: &EllipseToolData, tool_data: &DocumentToolData) -> Opera
 			style: style::PathStyle::new(None, Some(style::Fill::new(tool_data.primary_color))),
 		}
 	} else {
+		let (cx, cy, r_scale) = if data.center_around_cursor { (x0, y0, 1.0) } else { ((x0 + x1) * 0.5, (y0 + y1) * 0.5, 0.5) };
 		let (rx, ry) = ((x1 - x0).abs() * r_scale, (y1 - y0).abs() * r_scale);
 		Operation::AddEllipse {
 			path: vec![],