@@ -683,15 +683,19 @@ class Learner2D(BaseLearner):

         self._bounds_points = list(itertools.product(*bounds))

         # Add the loss improvement to the bounds in the stack

-        self._stack = [p + (np.inf,) for p in self._bounds_points]

+        self._bounds_points = [(x / self.x_scale, y / self.y_scale)

+                               for x, y in self._bounds_points]

+        self._stack = [(*p, np.inf) for p in self._bounds_points]

-        def f(xy):

+        self.original_function = function

+

+        def scaled_function(xy):

             x, y = xy

-            x /= self.x_scale

-            y /= self.y_scale

-            return function((x, y))

+            x *= self.x_scale

+            y *= self.y_scale

+            return self.original_function((x, y))

-        self.function = f

+        self.function = scaled_function

     @property

     def points_combined(self):