diff --git a/skopt/optimizer/optimizer.py b/skopt/optimizer/optimizer.py
index 5ca806a8..28923d72 100644
--- a/skopt/optimizer/optimizer.py
+++ b/skopt/optimizer/optimizer.py
@@ -291,6 +291,7 @@ def __init__(
         if type(dimensions) is CS.ConfigurationSpace:
             # Save the config space to do a real copy of the Optimizer
             self.config_space = dimensions
+            self.config_space.seed(self.rng.get_state()[1][0])
 
             if isinstance(self.base_estimator_, GaussianProcessRegressor):
                 raise RuntimeError("GP estimator is not available with ConfigSpace!")