diff --git a/mirgecom/thermochemistry.py b/mirgecom/thermochemistry.py
index a9ce1dc38..277bc09ff 100644
--- a/mirgecom/thermochemistry.py
+++ b/mirgecom/thermochemistry.py
@@ -85,7 +85,6 @@ class PyroWrapper(pyro_class):
         # This only affects chemistry-related evaluations and does not interfere
         # with the actual fluid state.
         def get_concentrations(self, rho, mass_fractions):
-            # concs = self.inv_molecular_weights * rho * mass_fractions
             concs = self.inv_molecular_weights * rho * mass_fractions
             # ensure non-negative concentrations
             zero = self._pyro_zeros_like(concs[0])
@@ -177,8 +176,7 @@ def get_heat_release_rate(self, state):
 
             heat_rls = state.cv.mass*0.0
             for i in range(self.num_species):
-                # heat_rls = heat_rls - h_a[i]*w_dot[i]/(self.molecular_weights[i])
-                heat_rls = heat_rls - h_a[i]*w_dot[i]/(self.wts[i])
+                heat_rls = heat_rls - h_a[i]*w_dot[i]/(self.molecular_weights[i])
 
             return heat_rls*self.gas_constant*state.temperature