diff --git a/neuroml/nml/helper_methods.py b/neuroml/nml/helper_methods.py
index 08c07f7..126bd6b 100644
--- a/neuroml/nml/helper_methods.py
+++ b/neuroml/nml/helper_methods.py
@@ -1617,6 +1617,12 @@ def add_segment(
 
         self.morphology.segments.append(segment)
 
+        # remove cached property since it is now outdated
+        try:
+            del self.__dict__['segment_ids_vs_segments']
+        except KeyError:
+            pass
+
         if optimise_segment_groups:
             self.optimise_segment_groups()
 
diff --git a/neuroml/nml/nml.py b/neuroml/nml/nml.py
index 8e08329..9146c24 100644
--- a/neuroml/nml/nml.py
+++ b/neuroml/nml/nml.py
@@ -2,7 +2,7 @@
 # -*- coding: utf-8 -*-
 
 #
-# Generated Wed Sep 11 17:09:38 2024 by generateDS.py version 2.44.1.
+# Generated Thu Sep 12 16:44:57 2024 by generateDS.py version 2.44.1.
 # Python 3.11.9 (main, Aug 23 2024, 00:00:00) [GCC 14.2.1 20240801 (Red Hat 14.2.1-1)]
 #
 # Command line options:
@@ -49179,6 +49179,12 @@ def add_segment(
 
         self.morphology.segments.append(segment)
 
+        # remove cached property since it is now outdated
+        try:
+            del self.__dict__["segment_ids_vs_segments"]
+        except KeyError:
+            pass
+
         if optimise_segment_groups:
             self.optimise_segment_groups()