diff --git a/freqtrade/strategy/hyper.py b/freqtrade/strategy/hyper.py
index 9a7fc4ba4..c72beba55 100644
--- a/freqtrade/strategy/hyper.py
+++ b/freqtrade/strategy/hyper.py
@@ -25,9 +25,8 @@ class BaseParameter(ABC):
     category: Optional[str]
     default: Any
     value: Any
-    opt_range: Sequence[Any]
 
-    def __init__(self, *, opt_range: Sequence[Any], default: Any, space: Optional[str] = None,
+    def __init__(self, *, default: Any, space: Optional[str] = None,
                  optimize: bool = True, load: bool = True, **kwargs):
         """
         Initialize hyperopt-optimizable parameter.
@@ -44,7 +43,6 @@ class BaseParameter(ABC):
         self.category = space
         self._space_params = kwargs
         self.value = default
-        self.opt_range = opt_range
         self.optimize = optimize
         self.load = load
 
@@ -69,7 +67,6 @@ class BaseParameter(ABC):
 class IntParameter(BaseParameter):
     default: int
     value: int
-    opt_range: Sequence[int]
 
     def __init__(self, low: Union[int, Sequence[int]], high: Optional[int] = None, *, default: int,
                  space: Optional[str] = None, optimize: bool = True, load: bool = True, **kwargs):
@@ -90,10 +87,12 @@ class IntParameter(BaseParameter):
         if high is None or isinstance(low, Sequence):
             if not isinstance(low, Sequence) or len(low) != 2:
                 raise OperationalException('IntParameter space must be [low, high]')
-            opt_range = low
+            self.low, self.high = low
         else:
-            opt_range = [low, high]
-        super().__init__(opt_range=opt_range, default=default, space=space, optimize=optimize,
+            self.low = low
+            self.high = high
+
+        super().__init__(default=default, space=space, optimize=optimize,
                          load=load, **kwargs)
 
     def get_space(self, name: str) -> 'Integer':
@@ -101,13 +100,12 @@ class IntParameter(BaseParameter):
         Create skopt optimization space.
         :param name: A name of parameter field.
         """
-        return Integer(*self.opt_range, name=name, **self._space_params)
+        return Integer(low=self.low, high=self.high, name=name, **self._space_params)
 
 
 class RealParameter(BaseParameter):
     default: float
     value: float
-    opt_range: Sequence[float]
 
     def __init__(self, low: Union[float, Sequence[float]], high: Optional[float] = None, *,
                  default: float, space: Optional[str] = None, optimize: bool = True,
@@ -129,10 +127,11 @@ class RealParameter(BaseParameter):
         if high is None or isinstance(low, Sequence):
             if not isinstance(low, Sequence) or len(low) != 2:
                 raise OperationalException(f'{self.__class__.__name__} space must be [low, high]')
-            opt_range = low
+            self.low, self.high = low
         else:
-            opt_range = [low, high]
-        super().__init__(opt_range=opt_range, default=default, space=space, optimize=optimize,
+            self.low = low
+            self.high = high
+        super().__init__(default=default, space=space, optimize=optimize,
                          load=load, **kwargs)
 
     def get_space(self, name: str) -> 'Real':
@@ -140,13 +139,12 @@ class RealParameter(BaseParameter):
         Create skopt optimization space.
         :param name: A name of parameter field.
         """
-        return Real(*self.opt_range, name=name, **self._space_params)
+        return Real(low=self.low, high=self.high, name=name, **self._space_params)
 
 
-class DecimalParameter(RealParameter):
+class DecimalParameter(BaseParameter):
     default: float
     value: float
-    opt_range: Sequence[float]
 
     def __init__(self, low: Union[float, Sequence[float]], high: Optional[float] = None, *,
                  default: float, decimals: int = 3, space: Optional[str] = None,
@@ -162,11 +160,22 @@ class DecimalParameter(RealParameter):
                       parameter fieldname is prefixed with 'buy_' or 'sell_'.
         :param optimize: Include parameter in hyperopt optimizations.
         :param load: Load parameter value from {space}_params.
-        :param kwargs: Extra parameters to skopt.space.Real.
+        :param kwargs: Extra parameters to skopt.space.Integer.
         """
         self._decimals = decimals
         default = round(default, self._decimals)
-        super().__init__(low=low, high=high, default=default, space=space, optimize=optimize,
+
+        if high is not None and isinstance(low, Sequence):
+            raise OperationalException(f'{self.__class__.__name__} space invalid.')
+        if high is None or isinstance(low, Sequence):
+            if not isinstance(low, Sequence) or len(low) != 2:
+                raise OperationalException(f'{self.__class__.__name__} space must be [low, high]')
+            self.low, self.high = low
+        else:
+            self.low = low
+            self.high = high
+
+        super().__init__(default=default, space=space, optimize=optimize,
                          load=load, **kwargs)
 
     def get_space(self, name: str) -> 'SKDecimal':
@@ -174,7 +183,7 @@ class DecimalParameter(RealParameter):
         Create skopt optimization space.
         :param name: A name of parameter field.
         """
-        return SKDecimal(*self.opt_range, decimals=self._decimals, name=name,
+        return SKDecimal(low=self.low, high=self.high, decimals=self._decimals, name=name,
                          **self._space_params)
 
 
@@ -200,7 +209,8 @@ class CategoricalParameter(BaseParameter):
         if len(categories) < 2:
             raise OperationalException(
                 'CategoricalParameter space must be [a, b, ...] (at least two parameters)')
-        super().__init__(opt_range=categories, default=default, space=space, optimize=optimize,
+        self.opt_range = categories
+        super().__init__(default=default, space=space, optimize=optimize,
                          load=load, **kwargs)
 
     def get_space(self, name: str) -> 'Categorical':