diff --git a/oletools/mraptor_milter.py b/oletools/mraptor_milter.py
index 2752090..969eaf2 100644
--- a/oletools/mraptor_milter.py
+++ b/oletools/mraptor_milter.py
@@ -137,6 +137,7 @@ log.setLevel(logging.CRITICAL+1)
 # === CLASSES ================================================================
 
 # Inspired from https://github.com/jmehnle/pymilter/blob/master/milter-template.py
+# TODO: check https://github.com/sdgathman/pymilter which looks more recent
 
 class MacroRaptorMilter(Milter.Base):
     '''
diff --git a/setup.py b/setup.py
index b50b3ab..8051207 100644
--- a/setup.py
+++ b/setup.py
@@ -41,7 +41,7 @@ import os, fnmatch
 #--- METADATA -----------------------------------------------------------------
 
 name         = "oletools"
-version      = '0.51a1'
+version      = '0.51dev2'
 desc         = "Python tools to analyze security characteristics of MS Office and OLE files (also called Structured Storage, Compound File Binary Format or Compound Document File Format), for Malware Analysis and Incident Response #DFIR"
 long_desc    = open('oletools/README.rst').read()
 author       = "Philippe Lagadec"