diff --git a/src/funcs_postprocess.py b/src/funcs_postprocess.py
index bc443c1..0dd8eb2 100644
--- a/src/funcs_postprocess.py
+++ b/src/funcs_postprocess.py
@@ -252,7 +252,7 @@ def get_graph_fitting(xPreSampled, zPreSampled, xErrors, zErrors):
     gr_oversampled.SetTitle(';X Position Aligned [#mum]; Relative Intensity')
     gr_oversampled.Draw('APL')
 
-    erf_func = TF1('erf_func', '[0]*0.5*(1 + TMath::Erf((x - [1])/[2])) + [3]')
+    erf_func = TF1('erf_func', '[0]*0.5*(1 + TMath::Erf((x - [1])/(TMath::Sqrt(2)*[2]))) + [3]')
     erf_func.SetLineColor(kRed+1)
     erf_func.SetParLimits(0, 0.2, 1.2) # amplitude
     erf_func.SetParLimits(1, -5*2.5, 5*2.5) # midpoint