diff --git a/skopt/optimizer/optimizer.py b/skopt/optimizer/optimizer.py
index 7bb5c2dbe..82bc6b791 100644
--- a/skopt/optimizer/optimizer.py
+++ b/skopt/optimizer/optimizer.py
@@ -301,9 +301,8 @@ def copy(self, random_state=None):
         random_state : int, RandomState instance, or None (default)
             Set the random state of the copy.
         """
-
         optimizer = Optimizer(
-            dimensions=self.space.dimensions,
+            dimensions=self.space.config_space if self.space.config_space != None else self.space.dimensions,
             base_estimator=self.base_estimator_,
             n_initial_points=self.n_initial_points_,
             initial_point_generator=self._initial_point_generator,