diff --git a/canaille/app/configuration.py b/canaille/app/configuration.py
index 556edef4..01d6bde1 100644
--- a/canaille/app/configuration.py
+++ b/canaille/app/configuration.py
@@ -132,8 +132,10 @@ def toml_content(file_path):
         with open(file_path, "rb") as fd:
             return tomllib.load(fd)
 
-    except ImportError:
-        raise Exception("toml library not installed. Cannot load configuration.")
+    except ImportError as exc:
+        raise Exception(
+            "toml library not installed. Cannot load configuration."
+        ) from exc
 
 
 def setup_config(app, config=None, test_config=True, env_file=".env", env_prefix=""):
diff --git a/canaille/backends/ldap/backend.py b/canaille/backends/ldap/backend.py
index 2d39b770..d96262cd 100644
--- a/canaille/backends/ldap/backend.py
+++ b/canaille/backends/ldap/backend.py
@@ -264,7 +264,7 @@ class LDAPBackend(Backend):
 
         class_filter = (
             "".join([f"(objectClass={oc})" for oc in model.ldap_object_class])
-            if getattr(model, "ldap_object_class")
+            if model.ldap_object_class
             else ""
         )
         if class_filter:
diff --git a/pyproject.toml b/pyproject.toml
index 58f47616..4186c737 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -170,6 +170,7 @@ exclude_lines = [
 
 [tool.ruff.lint]
 select = [
+    "B", # flake8-bugbear
     "E", # pycodestyle
     "F", # pyflakes
     "I", # isort