diff --git a/backend/geonature/core/gn_commons/models/abstract_mixin.py b/backend/geonature/core/gn_commons/models/abstract_mixin.py
index 3c068587d7..4c595b4771 100644
--- a/backend/geonature/core/gn_commons/models/abstract_mixin.py
+++ b/backend/geonature/core/gn_commons/models/abstract_mixin.py
@@ -1,9 +1,8 @@
 from .base import TModules
-import abc
 import typing
 
 
-class AbstractMixin(abc.ABC):
+class AbstractMixin:
     _module: TModules = None
 
     def __init__(self, module: TModules) -> None:
diff --git a/backend/geonature/core/gn_synthese/module.py b/backend/geonature/core/gn_synthese/module.py
index 9d50f6f1be..4dcf1b4ddc 100644
--- a/backend/geonature/core/gn_synthese/module.py
+++ b/backend/geonature/core/gn_synthese/module.py
@@ -1,10 +1,9 @@
 from geonature.core.gn_commons.models import TModules
 
 from geonature.core.gn_synthese.imports import SyntheseImportMixin
-from geonature.utils.metaclass_utils import metaclass_resolver
 
 
-class SyntheseModule(metaclass_resolver(TModules, SyntheseImportMixin)):
+class SyntheseModule(TModules, SyntheseImportMixin):
     __mapper_args__ = {"polymorphic_identity": "synthese"}
 
     def generate_input_url_for_dataset(self, dataset):
diff --git a/backend/geonature/core/imports/import_mixin.py b/backend/geonature/core/imports/import_mixin.py
index 55ab215ff3..3690135fae 100644
--- a/backend/geonature/core/imports/import_mixin.py
+++ b/backend/geonature/core/imports/import_mixin.py
@@ -3,7 +3,6 @@
 
 from bokeh.embed.standalone import StandaloneEmbedJson
 
-from abc import abstractmethod
 import typing
 
 
@@ -19,37 +18,30 @@ class ImportInputUrl(typing.TypedDict):
 
 class ImportMixin(AbstractMixin):
     @staticmethod
-    @abstractmethod
     def statistics_labels() -> typing.List[ImportStatisticsLabels]:
-        pass
+        raise NotImplementedError
 
     # The output of this method is NEVER used
     @staticmethod
-    @abstractmethod
     def preprocess_transient_data(imprt: TImports, df) -> set:
-        return None
+        raise NotImplementedError
 
     @staticmethod
-    @abstractmethod
     def check_transient_data(task, logger, imprt: TImports) -> None:
-        pass
+        raise NotImplementedError
 
     @staticmethod
-    @abstractmethod
     def import_data_to_destination(imprt: TImports) -> None:
-        pass
+        raise NotImplementedError
 
     @staticmethod
-    @abstractmethod
     def remove_data_from_destination(imprt: TImports) -> None:
-        pass
+        raise NotImplementedError
 
     @staticmethod
-    @abstractmethod
     def report_plot(imprt: TImports) -> StandaloneEmbedJson:
-        pass
+        raise NotImplementedError
 
     @staticmethod
-    @abstractmethod
     def compute_bounding_box(imprt: TImports) -> None:
-        pass
+        raise NotImplementedError
diff --git a/contrib/gn_module_occhab/backend/gn_module_occhab/module.py b/contrib/gn_module_occhab/backend/gn_module_occhab/module.py
index 1b99c070db..225ec60bbe 100644
--- a/contrib/gn_module_occhab/backend/gn_module_occhab/module.py
+++ b/contrib/gn_module_occhab/backend/gn_module_occhab/module.py
@@ -1,10 +1,9 @@
 from geonature.core.gn_commons.models import TModules
-from geonature.utils.metaclass_utils import metaclass_resolver
 
 from .imports import OcchabImportMixin
 
 
-class OcchabModule(metaclass_resolver(TModules, OcchabImportMixin)):
+class OcchabModule(TModules, OcchabImportMixin):
     __mapper_args__ = {"polymorphic_identity": "occhab"}
 
     def generate_input_url_for_dataset(self, dataset):