diff --git a/lib/binary/serialization.nit b/lib/binary/serialization.nit
index fff7fb5482..f4228b371b 100644
--- a/lib/binary/serialization.nit
+++ b/lib/binary/serialization.nit
@@ -178,7 +178,7 @@ class BinaryDeserializer
 
 			# An invalid attribute name is an heuristic for invalid data.
 			# Hitting an object end marker will result in an empty string.
-			assert next_attribute_name.is_valid_id else
+			if not next_attribute_name.is_valid_id then
 
 				var error
 				if next_attribute_name.is_empty then
diff --git a/lib/serialization/serialization.nit b/lib/serialization/serialization.nit
index 7ecc7d2f45..5630b34acd 100644
--- a/lib/serialization/serialization.nit
+++ b/lib/serialization/serialization.nit
@@ -148,7 +148,7 @@ abstract class Deserializer
 	var errors = new Array[Error]
 end
 
-# Deserialization got wrong attribute names
+# Error on invalid dynamic type for a deserialized attribute
 class AttributeTypeError
 	super Error
 
diff --git a/src/frontend/serialization_phase.nit b/src/frontend/serialization_phase.nit
index 6633e139ad..b9cab9d4a4 100644
--- a/src/frontend/serialization_phase.nit
+++ b/src/frontend/serialization_phase.nit
@@ -310,7 +310,7 @@ do
 			if type_name == "nullable Object" then
 				# Don't type check
 				code.add """
-	var {{{name}}} = v.deserialize_attribute("{{{attribute.serialize_name}}}", "{{{type_name}}}")
+	self.{{{name}}} = v.deserialize_attribute("{{{attribute.serialize_name}}}", "{{{type_name}}}")
 """
 			else code.add """
 	var {{{name}}} = v.deserialize_attribute("{{{attribute.serialize_name}}}", "{{{type_name}}}")