diff --git a/f2py/pygacode/cgyro/data_plot.py b/f2py/pygacode/cgyro/data_plot.py
index b7e8f51b1..309ee7106 100644
--- a/f2py/pygacode/cgyro/data_plot.py
+++ b/f2py/pygacode/cgyro/data_plot.py
@@ -55,7 +55,7 @@ def plot_freq(self,xin):
 
       # set normalizations
       t = self.getnorm(xin['norm'])
-
+     
       #======================================
       # Omega
       ax = fig.add_subplot(121)
@@ -70,6 +70,13 @@ def plot_freq(self,xin):
       ax.set_xlim([0,t[-1]])
       #======================================
 
+      # Alfven diagnostic
+      rho   = sum(self.mass*self.dens)
+      betae = self.betae_unit/self.b_gs2**2
+      v_A   = np.sqrt(2/(betae*rho))
+      w_TAE = v_A/(2*self.q*self.rmaj) 
+      ax.plot([0,t[-1]],[w_TAE,w_TAE],linestyle='--')
+
       #======================================
       # Gamma
       ax = fig.add_subplot(122)