diff --git a/stimuli/SinusAmplitudeModulation.py b/stimuli/SinusAmplitudeModulation.py
index 2296d28..8cbac1c 100644
--- a/stimuli/SinusAmplitudeModulation.py
+++ b/stimuli/SinusAmplitudeModulation.py
@@ -4,7 +4,7 @@ import numpy as np
 
 class SinusAmplitudeModulationStimulus(AbstractStimulus):
 
-    def __init__(self, carrier_frequency, amplitude, contrast, modulation_frequency, start_time=0, duration=np.inf):
+    def __init__(self, carrier_frequency, contrast, modulation_frequency, amplitude=1, start_time=0, duration=np.inf):
         self.contrast = contrast
         self.modulation_frequency = modulation_frequency
         self.amplitude = amplitude
diff --git a/tests/ModelTests.py b/tests/ModelTests.py
index f666f96..659a447 100644
--- a/tests/ModelTests.py
+++ b/tests/ModelTests.py
@@ -56,7 +56,7 @@ def test_lifac_noise():
     total_time = duration + 2*start
     step_size = model.get_parameters()["step_size"]/1000
     time = np.arange(0, total_time, step_size)
-    stimulus = SinusAmplitudeModulationStimulus(700, 20, 0.2, 10, start, duration)
+    stimulus = SinusAmplitudeModulationStimulus(700, 0.2, 10, 20, start, duration)
 
     model.simulate(stimulus, total_time)