diff --git a/fusion_accounting_followup/tests/__init__.py b/fusion_accounting_followup/tests/__init__.py
index 88f9ca6e..e78d0895 100644
--- a/fusion_accounting_followup/tests/__init__.py
+++ b/fusion_accounting_followup/tests/__init__.py
@@ -19,3 +19,4 @@ from . import test_followup_full_flow
 from . import test_performance_benchmarks
 from . import test_batch_followup_wizard
 from . import test_migration_round_trip
+from . import test_coexistence
diff --git a/fusion_accounting_followup/tests/test_coexistence.py b/fusion_accounting_followup/tests/test_coexistence.py
new file mode 100644
index 00000000..443b05ca
--- /dev/null
+++ b/fusion_accounting_followup/tests/test_coexistence.py
@@ -0,0 +1,37 @@
+"""Coexistence tests: fusion_accounting_followup menu only visible when
+Enterprise account_followup is NOT installed."""
+
+from odoo.tests.common import TransactionCase
+from odoo.tests import tagged
+
+
+@tagged('post_install', '-at_install')
+class TestFollowupCoexistence(TransactionCase):
+
+    def setUp(self):
+        super().setUp()
+        self.coex_group = self.env.ref(
+            'fusion_accounting_core.group_fusion_show_when_enterprise_absent',
+            raise_if_not_found=False,
+        )
+        self.assertIsNotNone(self.coex_group, "Coexistence group must exist")
+
+    def test_engine_always_available(self):
+        self.assertIn('fusion.followup.engine', self.env.registry)
+
+    def test_menu_gated_by_coexistence_group(self):
+        menu = self.env.ref('fusion_accounting_followup.menu_fusion_followup_root',
+                             raise_if_not_found=False)
+        if not menu:
+            self.skipTest("Menu not loaded")
+        menu_groups = getattr(menu, 'group_ids', None) or menu.groups_id
+        self.assertIn(self.coex_group, menu_groups,
+            "Followup root menu must require the coexistence group")
+
+    def test_levels_menu_gated(self):
+        menu = self.env.ref('fusion_accounting_followup.menu_fusion_followup_levels',
+                             raise_if_not_found=False)
+        if not menu:
+            self.skipTest("Menu not loaded")
+        menu_groups = getattr(menu, 'group_ids', None) or menu.groups_id
+        self.assertIn(self.coex_group, menu_groups)