diff --git a/shapes/Union.cc b/shapes/Union.cc
index 4f1eca4..a3257f9 100644
--- a/shapes/Union.cc
+++ b/shapes/Union.cc
@@ -33,7 +33,7 @@ Shape::IntersectionList Union::intersect(refptr<Shape> _this, const Ray & ray)
                 in1 = true;
             else
                 in2 = true;
-            if (!in_bool && in1 && in2)
+            if (!in_bool && (in1 || in2))
             {
                 /* we found an intersection point with the boolean object */
                 in_bool = true;
@@ -42,16 +42,16 @@ Shape::IntersectionList Union::intersect(refptr<Shape> _this, const Ray & ray)
         }
         else
         {
-            if (in_bool && in1 && in2)
-            {
-                /* we found an intersection point with the boolean object */
-                res.add( merged[i].intersection );
-            }
             if (left)
                 in1 = false;
             else
                 in2 = false;
-            in_bool = false;
+            if (in_bool && !(in1 || in2))
+            {
+                /* we found an intersection point with the boolean object */
+                res.add( merged[i].intersection );
+                in_bool = false;
+            }
         }
     }