diff --git a/benchmark/pytest/analysis/test_problem.py b/benchmark/pytest/analysis/test_problem.py
index 9c148818f..16aa886c3 100644
--- a/benchmark/pytest/analysis/test_problem.py
+++ b/benchmark/pytest/analysis/test_problem.py
@@ -13,6 +13,7 @@
 from glotaran.model import megacomplex
 from glotaran.parameter import ParameterGroup
 from glotaran.project import Scheme
+from glotaran.testing.plugin_system import monkeypatch_plugin_registry
 
 if TYPE_CHECKING:
     from glotaran.model import DatasetModel
@@ -53,6 +54,7 @@ def finalize_data(
         pass
 
 
+@monkeypatch_plugin_registry(test_megacomplex={"benchmark": BenchmarkMegacomplex})
 def setup_model(index_dependent):
     model_dict = {
         "megacomplex": {"m1": {"is_index_dependent": index_dependent}},
diff --git a/glotaran/model/model.py b/glotaran/model/model.py
index d69c20759..8d56c509c 100644
--- a/glotaran/model/model.py
+++ b/glotaran/model/model.py
@@ -85,7 +85,7 @@ def from_dict(
             }
         if default_megacomplex_type is not None:
             megacomplex_types[default_megacomplex_type] = get_megacomplex(default_megacomplex_type)
-            del model_dict["default-megacomplex"]
+            model_dict.pop("default-megacomplex", None)
 
         model = cls(
             megacomplex_types=megacomplex_types, default_megacomplex_type=default_megacomplex_type