diff --git a/blazar/db/sqlalchemy/api.py b/blazar/db/sqlalchemy/api.py
index 516736b60..0eaa22c2d 100644
--- a/blazar/db/sqlalchemy/api.py
+++ b/blazar/db/sqlalchemy/api.py
@@ -2045,6 +2045,7 @@ def resource_properties_list(resource_type):
             models.ExtraCapability.capability_name,
             models.ExtraCapability.private,
             resource_model.capability_value,
+            models.ExtraCapability.is_unique,
         ).join(resource_model), resource_model, deleted=False).distinct()
 
         return query.all()
diff --git a/blazar/db/sqlalchemy/models.py b/blazar/db/sqlalchemy/models.py
index b9fd4bcfe..72ca0d405 100644
--- a/blazar/db/sqlalchemy/models.py
+++ b/blazar/db/sqlalchemy/models.py
@@ -316,16 +316,19 @@ def to_dict(self):
 
     @validates('capability_value')
     def validate_capability_value(self, key, capability_value):
-        extra_capability = ExtraCapability.query.filter_by(id=self.capability_id).first()
+        from blazar.db.sqlalchemy import facade_wrapper
+        session = facade_wrapper.get_session()
+        extra_capability = session.query(ExtraCapability).filter_by(id=self.capability_id).first()
         if extra_capability and extra_capability.is_unique:
             existing_capability = (
-                self.query.filter_by(computehost_id=self.computehost_id,
+                session.query(ComputeHostExtraCapability).filter_by(computehost_id=self.computehost_id,
                                      capability_id=self.capability_id).first()
             )
             if existing_capability:
                 raise ValueError(
-                    f"{extra_capability.capability_name} is not unique "
-                    f"for compute_host {self.computehost_id}"
+                    f"{extra_capability.capability_name} must be unique. "
+                    f"Please select unique {extra_capability.capability_name} for "
+                    f"{self.computehost_id}"
                 )
         return capability_value
 
diff --git a/blazar/plugins/base.py b/blazar/plugins/base.py
index ae247f674..fd2ca3784 100644
--- a/blazar/plugins/base.py
+++ b/blazar/plugins/base.py
@@ -105,16 +105,20 @@ def on_start(self, resource_id, lease=None):
     def list_resource_properties(self, query):
         detail = False if not query else query.get('detail', False)
         resource_properties = collections.defaultdict(list)
+        is_property_unique = {}
 
-        for name, private, value in db_api.resource_properties_list(
+        for name, private, value, is_unique in db_api.resource_properties_list(
                 self.resource_type):
-
             if not private:
                 resource_properties[name].append(value)
+                is_property_unique[name] = is_unique
 
         if detail:
             return [
-                dict(property=k, private=False, values=v)
+                dict(
+                    property=k, private=False, values=v,
+                    is_unique=is_property_unique[k]
+                )
                 for k, v in resource_properties.items()]
         else:
             return [dict(property=k) for k, v in resource_properties.items()]
diff --git a/blazar/tests/db/sqlalchemy/test_sqlalchemy_api.py b/blazar/tests/db/sqlalchemy/test_sqlalchemy_api.py
index b11592320..da0d89738 100644
--- a/blazar/tests/db/sqlalchemy/test_sqlalchemy_api.py
+++ b/blazar/tests/db/sqlalchemy/test_sqlalchemy_api.py
@@ -551,7 +551,7 @@ def test_resource_properties_list(self):
 
         result = db_api.resource_properties_list('physical:host')
 
-        self.assertListEqual(result, [('vgpu', False, '2')])
+        self.assertListEqual(result, [('vgpu', False, '2', False)])
 
     def test_search_for_hosts_by_composed_queries(self):
         """Create one host and test composed queries."""
diff --git a/blazar/tests/plugins/networks/test_network_plugin.py b/blazar/tests/plugins/networks/test_network_plugin.py
index cb877335e..fc3c2f9a5 100644
--- a/blazar/tests/plugins/networks/test_network_plugin.py
+++ b/blazar/tests/plugins/networks/test_network_plugin.py
@@ -1036,11 +1036,11 @@ def test_list_resource_properties(self):
 
         # Expecting a list of (Reservation, Allocation)
         self.db_list_resource_properties.return_value = [
-            ('prop1', False, 'aaa'),
-            ('prop1', False, 'bbb'),
-            ('prop2', False, 'aaa'),
-            ('prop2', False, 'aaa'),
-            ('prop3', True, 'aaa')
+            ('prop1', False, 'aaa', False),
+            ('prop1', False, 'bbb', False),
+            ('prop2', False, 'aaa', False),
+            ('prop2', False, 'aaa', False),
+            ('prop3', True, 'aaa', False)
         ]
 
         expected = [
@@ -1063,15 +1063,15 @@ def test_list_resource_properties_with_detail(self):
 
         # Expecting a list of (Reservation, Allocation)
         self.db_list_resource_properties.return_value = [
-            ('prop1', False, 'aaa'),
-            ('prop1', False, 'bbb'),
-            ('prop2', False, 'ccc'),
-            ('prop3', True, 'aaa')
+            ('prop1', False, 'aaa', False),
+            ('prop1', False, 'bbb', False),
+            ('prop2', False, 'ccc', False),
+            ('prop3', True, 'aaa', False)
         ]
 
         expected = [
-            {'property': 'prop1', 'private': False, 'values': ['aaa', 'bbb']},
-            {'property': 'prop2', 'private': False, 'values': ['ccc']}
+            {'property': 'prop1', 'private': False, 'values': ['aaa', 'bbb'], 'is_unique': False},
+            {'property': 'prop2', 'private': False, 'values': ['ccc'], 'is_unique': False}
         ]
 
         ret = self.fake_network_plugin.list_resource_properties(
diff --git a/blazar/tests/plugins/oshosts/test_physical_host_plugin.py b/blazar/tests/plugins/oshosts/test_physical_host_plugin.py
index 3128b3b81..7e447117b 100644
--- a/blazar/tests/plugins/oshosts/test_physical_host_plugin.py
+++ b/blazar/tests/plugins/oshosts/test_physical_host_plugin.py
@@ -2549,16 +2549,16 @@ def test_list_resource_properties(self):
 
         # Expecting a list of (Reservation, Allocation)
         self.db_list_resource_properties.return_value = [
-            ('prop1', False, 'aaa'),
-            ('prop1', False, 'bbb'),
-            ('prop2', False, 'aaa'),
-            ('prop2', False, 'aaa'),
-            ('prop3', True, 'aaa')
+            ('prop1', False, 'aaa', False),
+            ('prop1', False, 'bbb', False),
+            ('prop2', False, 'aaa', False),
+            ('prop2', False, 'aaa', False),
+            ('prop3', True, 'aaa', False)
         ]
 
         expected = [
-            {'property': 'prop1'},
-            {'property': 'prop2'}
+            {'property': 'prop1',},
+            {'property': 'prop2',}
         ]
 
         ret = self.fake_phys_plugin.list_resource_properties(
@@ -2577,15 +2577,15 @@ def test_list_resource_properties_with_detail(self):
 
         # Expecting a list of (Reservation, Allocation)
         self.db_list_resource_properties.return_value = [
-            ('prop1', False, 'aaa'),
-            ('prop1', False, 'bbb'),
-            ('prop2', False, 'ccc'),
-            ('prop3', True, 'aaa')
+            ('prop1', False, 'aaa', False),
+            ('prop1', False, 'bbb', False),
+            ('prop2', False, 'ccc', False),
+            ('prop3', True, 'aaa', False)
         ]
 
         expected = [
-            {'property': 'prop1', 'private': False, 'values': ['aaa', 'bbb']},
-            {'property': 'prop2', 'private': False, 'values': ['ccc']}
+            {'property': 'prop1', 'private': False, 'values': ['aaa', 'bbb'], 'is_unique': False},
+            {'property': 'prop2', 'private': False, 'values': ['ccc'], 'is_unique': False}
         ]
 
         ret = self.fake_phys_plugin.list_resource_properties(