diff --git a/stimuli/AbstractStimulus.py b/stimuli/AbstractStimulus.py
index 0745fa5..aa38dc8 100644
--- a/stimuli/AbstractStimulus.py
+++ b/stimuli/AbstractStimulus.py
@@ -2,7 +2,7 @@
 class AbstractStimulus:
 
     def value_at_time_in_ms(self, time_point):
-        raise NotImplementedError("This is an abstract class!")
+        return self.value_at_time_in_s(time_point / 1000)
 
     def value_at_time_in_s(self, time_point):
         raise NotImplementedError("This is an abstract class!")
diff --git a/stimuli/StepStimulus.py b/stimuli/StepStimulus.py
index 261aefb..f0622ec 100644
--- a/stimuli/StepStimulus.py
+++ b/stimuli/StepStimulus.py
@@ -16,9 +16,6 @@ class StepStimulus(AbstractStimulus):
             self.start = start / 1000
             self.duration = duration / 1000
 
-    def value_at_time_in_ms(self, time_point):
-        return self.value_at_time_in_s(time_point/1000)
-
     def value_at_time_in_s(self, time_point):
         if self.start <= time_point <= self.start + self.duration:
             return self.value