diff --git a/freqtrade/optimize/hyperopt.py b/freqtrade/optimize/hyperopt.py
index c5a003bd6..e5e027d46 100644
--- a/freqtrade/optimize/hyperopt.py
+++ b/freqtrade/optimize/hyperopt.py
@@ -313,8 +313,7 @@ class Hyperopt:
 
         if self.has_space('trailing'):
             self.backtesting.strategy.trailing_stop = params['trailing_stop']
-            self.backtesting.strategy.trailing_stop_positive = \
-                params['trailing_stop_positive']
+            self.backtesting.strategy.trailing_stop_positive = params['trailing_stop_positive']
             self.backtesting.strategy.trailing_stop_positive_offset = \
                 params['trailing_stop_positive_offset']
             self.backtesting.strategy.trailing_only_offset_is_reached = \
diff --git a/freqtrade/optimize/hyperopt_interface.py b/freqtrade/optimize/hyperopt_interface.py
index e8f16d572..b4cfdcaf3 100644
--- a/freqtrade/optimize/hyperopt_interface.py
+++ b/freqtrade/optimize/hyperopt_interface.py
@@ -182,7 +182,14 @@ class IHyperOpt(ABC):
         You may override it in your custom Hyperopt class.
         """
         return [
-            Categorical([True, False], name='trailing_stop'),
+            # It was decided to always set trailing_stop is to True if the 'trailing' hyperspace
+            # is used. Otherwise hyperopt will vary other parameters that won't have effect if
+            # trailing_stop is set False.
+            # This parameter is included into the hyperspace dimensions rather than assigning
+            # it explicitly in the code in order to have it printed in the results along with
+            # other 'trailing' hyperspace parameters.
+            Categorical([True], name='trailing_stop'),
+
             Real(-0.35, -0.02, name='trailing_stop_positive'),
             Real(0.01, 0.1, name='trailing_stop_positive_offset'),
             Categorical([True, False], name='trailing_only_offset_is_reached'),