diff --git a/SBO_OBO.obo b/SBO_OBO.obo
index a149223..cde5b91 100644
--- a/SBO_OBO.obo
+++ b/SBO_OBO.obo
@@ -1178,7 +1178,7 @@ is_a: SBO:0000176 ! biochemical reaction
 [Term]
 id: SBO:0000178
 name: cleavage
-comment: Rupture of a covalent bond resulting in the conversion of one physical entity into several physical entities.
+comment: Rupture of a covalent bond resulting in the conversion of one physical entity into several physical entities or into a physical entity of a different topological class.
 is_a: SBO:0000182 ! conversion
 
 [Term]