diff --git a/source/include/sphere.h b/source/include/sphere.h
index 19151f3..b6cf710 100644
--- a/source/include/sphere.h
+++ b/source/include/sphere.h
@@ -16,7 +16,7 @@
 class Sphere : public Object
 {
 public:
-    /* All sphere are at (0, 0, 0) and radius 1*/
+    /* All sphere are at (0, 0, 0) and radius 1 in the object space */
     virtual Intersect intersect(Ray r);
 };