diff --git a/shapes/Cyl.cc b/shapes/Cyl.cc
index d6c7291..4b45b49 100644
--- a/shapes/Cyl.cc
+++ b/shapes/Cyl.cc
@@ -32,7 +32,7 @@ Shape::IntersectionList Cyl::intersect(refptr<Shape> _this, const Ray & ray)
         LinearSolver solver(-ray_inv.getDirection()[2],
                             -ray_inv.getOrigin()[2]);
         Solver::Result solutions = solver.solve();
-        if (solutions.numResults > 0)
+        if (solutions.numResults > 0 && solutions.results[0] > 0.0)
         {
             Vector isect_point = ray_inv[solutions.results[0]];
             if (isect_point[0]*isect_point[0] + isect_point[1]*isect_point[1]
@@ -50,7 +50,7 @@ Shape::IntersectionList Cyl::intersect(refptr<Shape> _this, const Ray & ray)
         LinearSolver solver(ray_inv.getDirection()[2],
                             ray_inv.getOrigin()[2] - m_height);
         Solver::Result solutions = solver.solve();
-        if (solutions.numResults > 0)
+        if (solutions.numResults > 0 && solutions.results[0] > 0.0)
         {
             Vector isect_point = ray_inv[solutions.results[0]];
             if (isect_point[0]*isect_point[0] + isect_point[1]*isect_point[1]