diff --git a/include/boost/geometry/strategies/cartesian/buffer_join_round.hpp b/include/boost/geometry/strategies/cartesian/buffer_join_round.hpp
index 0a37983fa..3423d3dcc 100644
--- a/include/boost/geometry/strategies/cartesian/buffer_join_round.hpp
+++ b/include/boost/geometry/strategies/cartesian/buffer_join_round.hpp
@@ -96,8 +96,8 @@ private :
         // - generates 1 point  in between for an angle of 125 based on 3 points
         // - generates 0 points in between for an angle of 90  based on 4 points
 
-        int const n = 1 + std::max(static_cast<int>(
-            ceil(-1.0 + m_points_per_circle * angle_diff / two_pi)), 0);
+        int const n = std::max(static_cast<int>(
+            ceil(m_points_per_circle * angle_diff / two_pi)), 1);
 
         PromotedType const diff = angle_diff / static_cast<PromotedType>(n);
         PromotedType a = angle1 - diff;