diff --git a/grudge/models/wave.py b/grudge/models/wave.py
index e7c66f0e355155663db5fff78ee40e1c892e4f43..ed0d40198397f070f9fba35300a0b932e99a1497 100644
--- a/grudge/models/wave.py
+++ b/grudge/models/wave.py
@@ -333,7 +333,7 @@ class VariableCoefficientWeakWaveOperator(HyperbolicOperator):
 
     def max_eigenvalue(self, t, fields=None, discr=None):
         actx = self.dcoll._setup_actx
-        return op.nodal_maximum(self.dcoll, actx.np.fabs(self.c))
+        return op.nodal_max(self.dcoll, "vol", actx.np.fabs(self.c))
 
 # }}}