diff --git a/freqtrade/optimize/hyperopt_auto.py b/freqtrade/optimize/hyperopt_auto.py
index fdc4da14c..41f086ad2 100644
--- a/freqtrade/optimize/hyperopt_auto.py
+++ b/freqtrade/optimize/hyperopt_auto.py
@@ -7,10 +7,10 @@ from typing import Any, Callable, Dict, List
 from pandas import DataFrame
 from skopt.space import Categorical, Dimension, Integer, Real  # noqa
 
+from freqtrade.exceptions import OperationalException
 from freqtrade.optimize.hyperopt_interface import IHyperOpt
 
 
-# noinspection PyUnresolvedReferences
 class HyperOptAuto(IHyperOpt):
     """
     This class delegates functionality to Strategy(IHyperStrategy) and Strategy.HyperOpt classes.
diff --git a/freqtrade/strategy/hyper.py b/freqtrade/strategy/hyper.py
index 8de986950..154dcead6 100644
--- a/freqtrade/strategy/hyper.py
+++ b/freqtrade/strategy/hyper.py
@@ -2,7 +2,7 @@
 IHyperStrategy interface, hyperoptable Parameter class.
 This module defines a base class for auto-hyperoptable strategies.
 """
-from typing import Iterator, Tuple, Any, Optional, Sequence
+from typing import Iterator, Tuple, Any, Optional, Sequence, Union
 
 from skopt.space import Integer, Real, Categorical
 
@@ -22,7 +22,8 @@ class BaseParameter(object):
                  **kwargs):
         """
         Initialize hyperopt-optimizable parameter.
-        :param category: A parameter category. Can be 'buy' or 'sell'. This parameter is optional if parameter field
+        :param category: A parameter category. Can be 'buy' or 'sell'. This parameter is optional if
+         parameter field
          name is prefixed with 'buy_' or 'sell_'.
         :param kwargs: Extra parameters to skopt.space.(Integer|Real|Categorical).
         """
@@ -37,6 +38,9 @@ class BaseParameter(object):
     def __repr__(self):
         return f'{self.__class__.__name__}({self.value})'
 
+    def get_space(self, name: str) -> Union[Integer, Real, Categorical]:
+        raise NotImplementedError()
+
 
 class IntParameter(BaseParameter):
     default: int
@@ -49,7 +53,8 @@ class IntParameter(BaseParameter):
         Initialize hyperopt-optimizable parameter.
         :param space: Optimization space, [min, max].
         :param default: A default value.
-        :param category: A parameter category. Can be 'buy' or 'sell'. This parameter is optional if parameter field
+        :param category: A parameter category. Can be 'buy' or 'sell'. This parameter is optional if
+         parameter field
          name is prefixed with 'buy_' or 'sell_'.
         :param kwargs: Extra parameters to skopt.space.Integer.
         """
@@ -76,7 +81,8 @@ class FloatParameter(BaseParameter):
         Initialize hyperopt-optimizable parameter.
         :param space: Optimization space, [min, max].
         :param default: A default value.
-        :param category: A parameter category. Can be 'buy' or 'sell'. This parameter is optional if parameter field
+        :param category: A parameter category. Can be 'buy' or 'sell'. This parameter is optional if
+         parameter field
          name is prefixed with 'buy_' or 'sell_'.
         :param kwargs: Extra parameters to skopt.space.Real.
         """