diff --git a/gwinc/ifo/noises.py b/gwinc/ifo/noises.py
index 344969e78cb0acf5012b751e6fcf7402f9c31694..555c01b1112876adadf50073300eaa5b5b17d257 100644
--- a/gwinc/ifo/noises.py
+++ b/gwinc/ifo/noises.py
@@ -112,13 +112,12 @@ def dhdl(f, armlen):
     omega_arm_b = (1 + sin(nu_small)) * pi * f * armlen / c
     sinc_sqr = 4 / abs(sin(omega_arm_f) * exp(-1j * omega_arm) / omega_arm_f
                        + sin(omega_arm_b) * exp(1j * omega_arm) / omega_arm_b)**2
-    # keep DC value equal to 1
-    sinc_sqr /= sinc_sqr[0]
     dhdl_sqr = sinc_sqr / armlen**2
     return dhdl_sqr, sinc_sqr
 
 ##################################################
 
+
 def precomp_mirror(f, ifo):
     ifo.Materials.MirrorVolume = \
         pi * ifo.Materials.MassRadius**2 \