diff --git a/src/regionModels/pyrolysisModels/reactingOneDim/reactingOneDim.C b/src/regionModels/pyrolysisModels/reactingOneDim/reactingOneDim.C
index 29325f602e..db31437057 100644
--- a/src/regionModels/pyrolysisModels/reactingOneDim/reactingOneDim.C
+++ b/src/regionModels/pyrolysisModels/reactingOneDim/reactingOneDim.C
@@ -323,6 +323,7 @@ void reactingOneDim::solveEnergy()
       - fvm::laplacian(alpha, h_)
      ==
         chemistrySh_
+      + fvm::Sp(solidChemistry_->RRg(), h_)
     );
 
     if (gasHSource_)