diff --git a/demos/boolean/primitives.geo b/demos/boolean/primitives.geo
index 76dff86381885e22fb48b66af8d0bcb932b1d771..38f3ba44762b77c11d523e3619e4af16493f5c9a 100644
--- a/demos/boolean/primitives.geo
+++ b/demos/boolean/primitives.geo
@@ -36,3 +36,19 @@ BSpline(6) = {7:12};
 Point(13) = {4,-2,0};     Point(14) = {4.1,-1.9,0};Point(15) = {4.2,-1.7,0};
 Point(16) = {4.3,-1.8,0}; Point(17) = {4.4,-2,0};  Point(18) = {4.5,-2.1,0};
 Bezier(7) = {13:18};
+
+Point(19) = {0,-2.7,0};  Point(20) = {0.2,-2.5,0}; Point(21) = {0.5,-2.5,0};
+Point(22) = {0.1,-3,0};  Point(23) = {0.5,-3,0};
+Line(8) = {19,20};
+Line(9) = {20,21};
+Bezier(10) = {21,23,22,19};
+Line Loop(1) = {8,9,10};
+Plane Surface(4) = {1};
+
+Point(24) = {1,-2.7,0};  Point(25) = {1.2,-2.5,0.2}; Point(26) = {1.5,-2.5,0};
+Point(27) = {1.1,-3,0};  Point(28) = {1.5,-3,0.5};
+Line(11) = {24,25};
+Line(12) = {25,26};
+Bezier(13) = {26,28,27,24};
+Line Loop(2) = {11,12,13};
+Ruled Surface(5) = {2};