diff --git a/matlab/load_params.m b/matlab/load_params.m
index 5443658e8856e51f84100e3ce2e0929fa49a34a6..b7fd6315f2fe2a4673f3a1f9b24290ce1b61631b 100644
--- a/matlab/load_params.m
+++ b/matlab/load_params.m
@@ -7,7 +7,7 @@ JMAXI   = h5readatt(filename,'/data/input','jmaxi');
 PMAXE   = h5readatt(filename,'/data/input','pmaxe');
 JMAXE   = h5readatt(filename,'/data/input','jmaxe');
 NON_LIN = h5readatt(filename,'/data/input','NON_LIN');
-NU      = h5readatt(filename,'/data/input','nu')/0.532;
+NU      = h5readatt(filename,'/data/input','nu');
 NR      = h5readatt(filename,'/data/input','nr');
 NZ      = h5readatt(filename,'/data/input','nz');
 L       = h5readatt(filename,'/data/input','Lr');
diff --git a/src/model_mod.F90 b/src/model_mod.F90
index bd3ff52157f75d5aca8519beae4223cb86c544a3..3b77badcdb76b4fcc9d976771d3858645530afbe 100644
--- a/src/model_mod.F90
+++ b/src/model_mod.F90
@@ -69,18 +69,13 @@ CONTAINS
     qi2_taui        = (q_i**2)/tau_i
     sigmae2_taue_o2 = sigma_e**2 * tau_e/2._dp ! factor of the Kernel argument
     sigmai2_taui_o2 = sigma_i**2 * tau_i/2._dp
-    !! We must change the normalization of the collisionality according to the collision model
-    IF (ABS(CO) .GT. 1) THEN ! If using COSOlver mat (2 Sugama, 3 Coulomb)
-      nu_e            = 0.532_dp*nu/sigma_e * (tau_e)**(3._dp/2._dp)  ! electron-ion collision frequency (where already multiplied by 0.532)
-      nu_i            = 0.532_dp*nu ! ion-ion collision frequ.
-      nu_ee           = nu_e ! e-e coll. frequ.
-      nu_ie           = nu_i ! i-e coll. frequ.
-    ELSE ! If we use an ad hoc collision operator as Dougherty or Lenhard-Bernstein
-      nu_e            = 0.532_dp*nu ! electron-ion collision frequency
-      nu_i            = 0.532_dp*nu * sigma_e * (tau_i)**(-3._dp/2._dp)/SQRT2 ! ion-ion collision frequ.
-      nu_ee           = nu_e/SQRT2 ! e-e coll. frequ.
-      nu_ie           = nu*sigma_e**2 ! i-e coll. frequ.
-    ENDIF
+    !! We use the ion-ion collision as normalization with definition
+    !   nu_ii = 4 sqrt(pi)/3 T_i^(-3/2) m_i^(-1/2) q^4 n_i0 ln(Lambda)
+    !
+    nu_e            = nu/sigma_e * (tau_e)**(3._dp/2._dp)  ! electron-ion collision frequency (where already multiplied by 0.532)
+    nu_i            = nu ! ion-ion collision frequ.
+    nu_ee           = nu_e ! e-e coll. frequ.
+    nu_ie           = nu_i ! i-e coll. frequ.
   END SUBROUTINE model_readinputs