diff --git a/serialization/errors.nim b/serialization/errors.nim
index 42e94a4..42cf615 100644
--- a/serialization/errors.nim
+++ b/serialization/errors.nim
@@ -2,3 +2,6 @@ type
   SerializationError* = object of CatchableError
   UnexpectedEofError* = object of SerializationError
 
+method formatMsg*(err: ref SerializationError, filename: string): string {.base.} =
+  "Serialisation error while processing " & filename
+