diff --git a/user_libs/optimisations/taguchi_fitness.py b/user_libs/optimisations/taguchi_fitness.py
index 99037201..93ebded2 100644
--- a/user_libs/optimisations/taguchi_fitness.py
+++ b/user_libs/optimisations/taguchi_fitness.py
@@ -143,6 +143,7 @@ def fitness_diffs(filename, args):
             # Calculate sum of differences
             tmp = 20 * np.log10(np.abs(modelresp - refresp) / np.amax(np.abs(refresp)))
             tmp = np.abs(np.sum(tmp[-np.isneginf(tmp)])) / len(tmp[-np.isneginf(tmp)])
+            diffdB += tmp
 
     return diffdB