diff --git a/auth_oidc/models/auth_oauth_provider.py b/auth_oidc/models/auth_oauth_provider.py
index b048459a81..898e4d0f16 100644
--- a/auth_oidc/models/auth_oauth_provider.py
+++ b/auth_oidc/models/auth_oauth_provider.py
@@ -129,8 +129,12 @@ def _check_expression(self):
         for this in self:
             try:
                 this._eval_expression(self.env.user, {})
-            except (AttributeError, KeyError, NameError) as e:
-                raise exceptions.ValidationError("\n".join(e.args)) from e
+            except (AttributeError, KeyError, NameError, ValueError) as e:
+                # AttributeError: user object can be accessed via attributes: user.email
+                # KeyError: token is a dict of dicts
+                # NameError: only user and token can be used
+                # ValueError: for inexistant variables or attributes
+                raise exceptions.ValidationError(e) from e
 
     def _eval_expression(self, user, token):
         self.ensure_one()
diff --git a/auth_oidc/tests/test_auth_oidc_auth_code.py b/auth_oidc/tests/test_auth_oidc_auth_code.py
index a08d250cef..c89a85eed1 100644
--- a/auth_oidc/tests/test_auth_oidc_auth_code.py
+++ b/auth_oidc/tests/test_auth_oidc_auth_code.py
@@ -13,7 +13,7 @@
 from jose.utils import long_to_base64
 
 import odoo
-from odoo.exceptions import AccessDenied
+from odoo.exceptions import AccessDenied, ValidationError
 from odoo.tests import common
 
 from odoo.addons.website.tools import MockRequest as _MockRequest
@@ -340,3 +340,26 @@ def test_group_expressions_with_token(self):
         self.assertFalse(
             group_line._eval_expression(self.env.user, {"groups": ["group-c"]})
         )
+
+    def test_group_expression_with_inexistant_variable(self):
+        """Test that group expression with inexistant variable fails"""
+        group_line = self.env.ref("auth_oidc.local_keycloak").group_line_ids[:1]
+
+        with self.assertRaises(ValidationError):
+            group_line.expression = "inexistant_variable"
+
+    def test_group_expression_with_inexistant_attribute(self):
+        """Test that group expression with inexistant attribute (on user) fails"""
+        group_line = self.env.ref("auth_oidc.local_keycloak").group_line_ids[:1]
+
+        with self.assertRaises(ValidationError):
+            group_line.expression = "user.not_an_attribute"
+
+    def test_realistic_group_expression(self):
+        """Test that group expression with inexistant attribute (on user) fails"""
+        group_line = self.env.ref("auth_oidc.local_keycloak").group_line_ids[:1]
+
+        group_line.expression = "user.email == token['mail']"
+        self.assertTrue(
+            group_line._eval_expression(self.env.user, {"mail": self.env.user.email})
+        )