diff --git a/galpy/potential_src/TwoPowerSphericalPotential.py b/galpy/potential_src/TwoPowerSphericalPotential.py
index <HASH>..<HASH> 100644
--- a/galpy/potential_src/TwoPowerSphericalPotential.py
+++ b/galpy/potential_src/TwoPowerSphericalPotential.py
@@ -312,6 +312,7 @@ class HernquistPotential(TwoPowerIntegerSphericalPotential):
         self.beta= 4
         if normalize:
             self.normalize(normalize)
+        self.hasC= True
         return None
 
     def _evaluate(self,R,z,phi=0.,t=0.,dR=0,dphi=0):
add C implementation of Hernquist potential