diff --git a/src/HierarchicalSystem.java b/src/HierarchicalSystem.java
index f17adf9..86b8f48 100644
--- a/src/HierarchicalSystem.java
+++ b/src/HierarchicalSystem.java
@@ -1,6 +1,6 @@
 /**
  * A cosmic system that is composed of a central named body (of type 'NamedBodyForcePair')
- * and an arbitrary number of subsystems (of type 'HierarchicalSystem') in its orbit.
+ * and an arbitrary number of subsystems (of type 'CosmicSystem') in its orbit.
  * This class implements 'CosmicSystem'.
  */
 public class HierarchicalSystem /* TODO: add clause */ {