diff --git a/alab_management/_default/tasks/default_task.py b/alab_management/_default/tasks/default_task.py
index 166b3234..9455c570 100644
--- a/alab_management/_default/tasks/default_task.py
+++ b/alab_management/_default/tasks/default_task.py
@@ -20,9 +20,15 @@ def run(self):
                 self.sample, sample_positions[None]["DefaultSamplePosition"][0]
             )
 
-    def validate(self):
+    def validate(self) -> bool:
+        """
+        Validation of the input parameters.
+
+        You can add more validation logic here. The method should return True if the input parameters
+        are valid, False otherwise. This method is called when you build the task.
+        """
         return True
 
     @property
-    def result_specification(self) -> BaseModel:
+    def result_specification(self) -> type[BaseModel]:
         pass
diff --git a/alab_management/task_view/task.py b/alab_management/task_view/task.py
index f5b876fe..0ea0c4ec 100644
--- a/alab_management/task_view/task.py
+++ b/alab_management/task_view/task.py
@@ -94,8 +94,6 @@ def __init__(self, sample_1: ObjectId, sample_2: Optional[ObjectId],
                 for key, val in inspect.getargvalues(subclass_init_frame).locals.items()
                 if key not in ["self", "args", "kwargs", "__class__"]
             }
-            if not self.validate():
-                raise ValueError("Task validation failed!")
         else:
             if (task_id is None) or (lab_view is None) or (samples is None):
                 raise ValueError(
@@ -108,6 +106,9 @@ def __init__(self, sample_1: ObjectId, sample_2: Optional[ObjectId],
             self.priority = priority
             self.lab_view.priority = priority
 
+            if not self.validate():
+                raise ValueError("Task validation failed!")
+
     @property
     def is_offline(self) -> bool:
         """Returns True if this task is in offline, False if it is a live task."""