diff --git a/Gemfile.devel b/Gemfile.devel
index c54ba0c..d220bfa 100644
--- a/Gemfile.devel
+++ b/Gemfile.devel
@@ -1,2 +1,3 @@
 gem 'plurimath', github: 'plurimath/plurimath', branch: 'features/lutaml_model_for_mathml'
 gem "mml", github: 'plurimath/mml', branch: 'features/mathml_parsing'
+gem "lutaml-model", github: 'lutaml/lutaml-model', branch: 'default-namespace-for-xml-mapping'