diff --git a/pybossa/sched.py b/pybossa/sched.py
index ab3a888ed6..59359f6c33 100644
--- a/pybossa/sched.py
+++ b/pybossa/sched.py
@@ -442,6 +442,11 @@ def get_reserve_task_category_info(reserve_task_config, project_id, timeout, use
     if not reserve_task_config:
         return sql_filters, category_keys
 
+    if current_app.config.get('PRIVATE_INSTANCE'):
+        current_app.logger.info("Reserve task by category disabled for private instance. project_id %s, reserve_task_config %s",
+            project_id, str(reserve_task_config))
+        return sql_filters, category_keys
+
     category = ":".join(["{}:*".format(field) for field in sorted(reserve_task_config)])
     lock_manager = LockManager(sentinel.master, timeout)
     category_keys = lock_manager.get_task_category_lock(project_id, user_id, category, exclude_user)
diff --git a/test/test_reserve_task_category.py b/test/test_reserve_task_category.py
index 81e9061cea..8bb2e4a1da 100644
--- a/test/test_reserve_task_category.py
+++ b/test/test_reserve_task_category.py
@@ -143,6 +143,13 @@ def test_get_reserve_task_category_info(self, get_task_category_lock):
         assert sql_filters == expected_sql_filter and \
             category_keys == expected_category_keys, "sql_filters, category_keys must be non empty"
 
+        # reserve task disabled for private instance,
+        with patch.dict(self.flask_app.config, {'PRIVATE_INSTANCE': True}):
+            sql_filters, category_keys = get_reserve_task_category_info(reserve_task_config, project.id, timeout, owner.id)
+            assert not sql_filters, "sql_filters must be empty for private instance"
+            assert not category_keys, "sql_filters must be empty for private instance"
+
+
     @with_context
     def test_acquire_and_release_reserve_task_lock(self):
         user = UserFactory.create()