diff --git a/collective_effects/resistive_wall.py b/collective_effects/resistive_wall.py
index d3ae1247a854b33be05fc9a726513d4e38ccabce..08500d409c7c0e4a01198117c271238e3a4026eb 100644
--- a/collective_effects/resistive_wall.py
+++ b/collective_effects/resistive_wall.py
@@ -151,7 +151,7 @@ class CircularResistiveWall(WakeField):
         else:
             wl = (-1/(4*np.pi * self.radius) 
                   * np.sqrt(Z0 * self.rho / (c * np.pi) ) 
-                  / time**(3/2) )
+                  / time**(3/2) ) * self.length
             ind = np.isnan(wl)
             wl[ind] = 0