diff --git a/code/python/feature_extraction/tsfeature/feature_fft.py b/code/python/feature_extraction/tsfeature/feature_fft.py
index 88d50ed..cdb924f 100644
--- a/code/python/feature_extraction/tsfeature/feature_fft.py
+++ b/code/python/feature_extraction/tsfeature/feature_fft.py
@@ -95,7 +95,7 @@ def fft_shape_skew(self):
 
     def fft_shape_kurt(self):
         shape_mean = self.fft_shape_mean()
-        np.sum([np.power((x - shape_mean), 4) * self.freq_spectrum[x] - 3
+        return np.sum([np.power((x - shape_mean), 4) * self.freq_spectrum[x] - 3
                 for x in range(len(self.freq_spectrum))]) / self._freq_sum_
 
     def fft_all(self):