diff --git a/tupak/gw/waveform_generator.py b/tupak/gw/waveform_generator.py
index dffacc16036275307be24f1f260f4650165e9c58..b5349c125cb2b28a9b8bb9efd5687387af0b0457 100644
--- a/tupak/gw/waveform_generator.py
+++ b/tupak/gw/waveform_generator.py
@@ -6,7 +6,7 @@ import numpy as np
 
 class WaveformGenerator(object):
 
-    def __init__(self, time_duration, sampling_frequency, start_time=0, frequency_domain_source_model=None,
+    def __init__(self, time_duration, sampling_frequency, star_time=0, frequency_domain_source_model=None,
                  time_domain_source_model=None, parameters=None, parameter_conversion=None,
                  non_standard_sampling_parameter_keys=None,
                  waveform_arguments=None):