diff --git a/pina/problem/abstract_problem.py b/pina/problem/abstract_problem.py
index c3abf4b..eae28bf 100644
--- a/pina/problem/abstract_problem.py
+++ b/pina/problem/abstract_problem.py
@@ -197,15 +197,15 @@ class AbstractProblem(metaclass=ABCMeta):
             pts = merge_tensors(samples)
             self.input_pts[location] = pts
 
-            if device:
-                self.input_pts[location] = self.input_pts[location].to(device=device) #TODO better fix
-                
-            # setting the grad
-            self.input_pts[location].requires_grad_(True)
-            self.input_pts[location].retain_grad()
             # the condition is sampled if input_pts contains all labels
             if sorted(self.input_pts[location].labels) ==  sorted(self.input_variables): 
                 self._have_sampled_points[location] = True
+                # setting device
+                if device:
+                    self.input_pts[location] = self.input_pts[location].to(device=device) #TODO better fix
+                # setting the grad
+                self.input_pts[location].requires_grad_(True)
+                self.input_pts[location].retain_grad()
 
     @property
     def have_sampled_points(self):