diff --git a/scintillation/Calibrationlib.py b/scintillation/Calibrationlib.py
index a941bf674afb4b91c1bcbb187a0a7acdebdae529..0c9974047edc7d48046baa9b8b5f9aef776c2cae 100644
--- a/scintillation/Calibrationlib.py
+++ b/scintillation/Calibrationlib.py
@@ -54,7 +54,7 @@ def model_flux(calibrator, frequency):
     flux_model = 0
     freqs = frequency*1.e-3# convert from MHz to GHz
     for j,p in enumerate(parameters):
-        flux_model += p*np.log10(frequency)**j
+        flux_model += p*np.log10(freqs)**j
     flux_model = 10**flux_model # because at first the flux is in log10
     return flux_model