diff --git a/Cartesian_kernel/include/CGAL/predicates/kernel_ftC2.h b/Cartesian_kernel/include/CGAL/predicates/kernel_ftC2.h
index e6da15d2547..56903c2c921 100644
--- a/Cartesian_kernel/include/CGAL/predicates/kernel_ftC2.h
+++ b/Cartesian_kernel/include/CGAL/predicates/kernel_ftC2.h
@@ -717,16 +717,16 @@ circumcenter_oriented_side_of_oriented_segmentC2(const FT& ax,  const FT& ay,
                                                  const FT& p2x, const FT& p2y)
 {
   const FT dX = bx - ax;
-  const FT dY = bx - ay;
-  const FT R0 = p0x * p0x + p0x * p0x;
-  const FT R1 = p1x * p1x + p1x * p1x;
-  const FT R2 = p2x * p2x + p2x * p2x;
-  const FT denominator = (p1x - p0x) * (p2x - p0x) +
-                         (p0x - p2x) * (p1x - p0x);
+  const FT dY = by - ay;
+  const FT R0 = p0x * p0x + p0y * p0y;
+  const FT R1 = p1x * p1x + p1y * p1y;
+  const FT R2 = p2x * p2x + p2y * p2y;
+  const FT denominator = (p1x - p0x) * (p2y - p0y) +
+                         (p0x - p2x) * (p1y - p0y);
   const FT det = 2 * denominator * (ax * dY - ay * dX)
-                   - (R2 - R1) * (p0x * dX + p0x * dY)
-                   - (R0 - R2) * (p1x * dX + p1x * dY)
-                   - (R1 - R0) * (p2x * dX + p2x * dY);
+                   - (R2 - R1) * (p0x * dX + p0y * dY)
+                   - (R0 - R2) * (p1x * dX + p1y * dY)
+                   - (R1 - R0) * (p2x * dX + p2y * dY);
   return CGAL::sign(det);
 }