X-Git-Url: http://nitlanguage.org

diff --git a/lib/core/collection/abstract_collection.nit b/lib/core/collection/abstract_collection.nit
index 5cffbec..5ed911f 100644
--- a/lib/core/collection/abstract_collection.nit
+++ b/lib/core/collection/abstract_collection.nit
@@ -457,7 +457,9 @@ interface Set[E]
 		var res = 23 + length
 		# Note: the order of the elements must not change the hash value.
 		# So, unlike usual hash functions, the accumulator is not combined with itself.
-		for e in self do res += e.hash
+		for e in self do
+			if e != null then res += e.hash
+		end
 		return res
 	end