diff --git a/csla_binary/binary_reader.py b/csla_binary/binary_reader.py
index 602e6c0..fb06364 100644
--- a/csla_binary/binary_reader.py
+++ b/csla_binary/binary_reader.py
@@ -205,7 +205,7 @@ class CslaBinaryReader:
 			return [self.read_int32() for _ in range(length)]
 		
 		if known_type == CslaKnownTypes.Null.value:
-			raise NotImplementedError()
+			return None
 		
 		if known_type == CslaKnownTypes.StringWithDictionaryKey.value:
 			system_string = self.read_string()