diff --git a/src/GeometryEvaluator.cc b/src/GeometryEvaluator.cc
index 719c6ed7..72490314 100644
--- a/src/GeometryEvaluator.cc
+++ b/src/GeometryEvaluator.cc
@@ -953,9 +953,10 @@ Response GeometryEvaluator::visit(State &state, const ProjectionNode &node)
 					}
 					if (!Nptr->isEmpty()) {
 						Polygon2d *poly = CGALUtils::project(*Nptr, node.cut_mode);
-						assert(poly);
-						poly->setConvexity(node.convexity);
-						geom.reset(poly);
+						if (poly) {
+							poly->setConvexity(node.convexity);
+							geom.reset(poly);
+						}
 					}
 				}
 			}
diff --git a/tests/regression/dumptest/projection-cut-tests-expected.csg b/tests/regression/dumptest/projection-cut-tests-expected.csg
index 5ee575af..fde98f48 100644
--- a/tests/regression/dumptest/projection-cut-tests-expected.csg
+++ b/tests/regression/dumptest/projection-cut-tests-expected.csg
@@ -14,6 +14,11 @@ group() {
 			}
 		}
 	}
+	projection(cut = true, convexity = 0) {
+		multmatrix([[1, 0, 0, 0], [0, 1, 0, 0], [0, 0, 1, 5], [0, 0, 0, 1]]) {
+			cube(size = [5, 5, 5], center = true);
+		}
+	}
 	multmatrix([[1, 0, 0, 0], [0, 1, 0, -10], [0, 0, 1, 0], [0, 0, 0, 1]]) {
 		projection(cut = true, convexity = 0) {
 			union() {