diff --git a/maintenance_plan/models/maintenance_plan.py b/maintenance_plan/models/maintenance_plan.py
index 05786f0f4..649e7e2ac 100644
--- a/maintenance_plan/models/maintenance_plan.py
+++ b/maintenance_plan/models/maintenance_plan.py
@@ -101,7 +101,9 @@ class MaintenancePlan(models.Model):
 
     @api.model
     def _search_search_equipment(self, operator, value):
-        if operator != "=" or (not value and not isinstance(value, models.NewId)):
+        if operator not in ("=", "in") or (
+            not value and not isinstance(value, models.NewId)
+        ):
             raise ValueError(self.env._("Unsupported search operator"))
         plans = self.search([("generate_with_domain", "=", True)])
         plan_ids = []
@@ -113,7 +115,7 @@ def _search_search_equipment(self, operator, value):
                 )
             ):
                 plan_ids.append(plan.id)
-        return ["|", ("equipment_id", "=", value), ("id", "in", plan_ids)]
+        return ["|", ("equipment_id", operator, value), ("id", "in", plan_ids)]
 
     @api.depends("equipment_id")
     def _compute_search_equipment(self):
diff --git a/maintenance_plan/readme/CONTRIBUTORS.md b/maintenance_plan/readme/CONTRIBUTORS.md
index 844c15a08..0f23ccebe 100644
--- a/maintenance_plan/readme/CONTRIBUTORS.md
+++ b/maintenance_plan/readme/CONTRIBUTORS.md
@@ -7,3 +7,4 @@
 - Enric Tobella \<<enric.tobella@dixmit.com>\>
 - Alexei Rivera \<<arivera@archeti.com>\>
 - Yann Papouin \<<ypa@decgroupe.com>\>
+- Yannick Payot \<<yannick.payot@acsone.eu>\>
diff --git a/maintenance_plan/tests/__init__.py b/maintenance_plan/tests/__init__.py
index def774ebc..69d1cd78c 100644
--- a/maintenance_plan/tests/__init__.py
+++ b/maintenance_plan/tests/__init__.py
@@ -1,2 +1,3 @@
 from . import test_maintenance_plan
 from . import test_maintenance_plan_domain
+from . import test_equipment_count
diff --git a/maintenance_plan/tests/test_equipment_count.py b/maintenance_plan/tests/test_equipment_count.py
new file mode 100644
index 000000000..598e97bc1
--- /dev/null
+++ b/maintenance_plan/tests/test_equipment_count.py
@@ -0,0 +1,87 @@
+# Copyright 2026 ACSONE SA/NV
+# License AGPL-3.0 or later (http://www.gnu.org/licenses/agpl).
+
+from .common import TestMaintenanceBase
+
+
+class TestEquipmentCount(TestMaintenanceBase):
+    """Test _compute_search_maintenance_plan_count in maintenance.equipment"""
+
+    def test_search_maintenance_plan_count_zero(self):
+        """Test search_maintenance_plan_count when no plans exist"""
+        # Create a new equipment with no maintenance plans
+        equipment = self.MaintenanceEquipment.create(
+            {
+                "name": "Equipment No Plans",
+            }
+        )
+        equipment._compute_search_maintenance_plan_count()
+        self.assertEqual(
+            equipment.search_maintenance_plan_count,
+            0,
+            "search_maintenance_plan_count should be 0 when no plans exist",
+        )
+
+    def test_search_maintenance_plan_count_one(self):
+        """Test search_maintenance_plan_count with one active plan"""
+        # Create a maintenance plan for the equipment
+        self.MaintenancePlan.create(
+            {
+                "equipment_id": self.equipment.id,
+                "maintenance_kind_id": self.maintenance_kind.id,
+            }
+        )
+        self.equipment._compute_search_maintenance_plan_count()
+        self.assertGreaterEqual(
+            self.equipment.search_maintenance_plan_count,
+            1,
+            "search_maintenance_plan_count should be at least 1 when plan exists",
+        )
+
+    def test_search_maintenance_plan_count_multiple(self):
+        """Test search_maintenance_plan_count with multiple plans"""
+        # Create a second maintenance kind
+        kind2 = self.MaintenanceKind.create(
+            {
+                "name": "Second Kind",
+                "code": "SECOND_KIND",
+                "priority": "optional",
+            }
+        )
+        # Create multiple maintenance plans for the equipment with different kinds
+        self.MaintenancePlan.create(
+            [
+                {
+                    "equipment_id": self.equipment.id,
+                    "maintenance_kind_id": self.maintenance_kind.id,
+                },
+                {
+                    "equipment_id": self.equipment.id,
+                    "maintenance_kind_id": kind2.id,
+                },
+            ]
+        )
+
+        self.equipment._compute_search_maintenance_plan_count()
+        self.assertGreaterEqual(
+            self.equipment.search_maintenance_plan_count,
+            2,
+            "search_maintenance_plan_count should be at least 2 when multiple plans exist",
+        )
+
+    def test_search_maintenance_plan_count_with_inactive(self):
+        """Test search_maintenance_plan_count includes inactive plans"""
+        # Create an inactive plan
+        self.MaintenancePlan.create(
+            {
+                "equipment_id": self.equipment.id,
+                "maintenance_kind_id": self.maintenance_kind.id,
+                "active": False,
+            }
+        )
+        self.equipment._compute_search_maintenance_plan_count()
+        self.assertGreaterEqual(
+            self.equipment.search_maintenance_plan_count,
+            1,
+            "search_maintenance_plan_count should include inactive plans",
+        )