diff --git a/python/swiftest/swiftest/io.py b/python/swiftest/swiftest/io.py
index 0b29bc5d5..a8c2daf08 100644
--- a/python/swiftest/swiftest/io.py
+++ b/python/swiftest/swiftest/io.py
@@ -5,7 +5,7 @@
 import sys
 import tempfile
 
-newfeaturelist = ("FRAGMENTATION", "ROTATION", "TIDES", "ENERGY", "GR", "YARKOVSKY", "YORP")
+newfeaturelist = ("FRAGMENTATION", "ROTATION", "TIDES", "ENERGY", "GR", "YARKOVSKY", "YORP", "IN_FORM")
 
 def real2float(realstr):
     """