diff --git a/applications/solvers/combustion/PDRFoam/PDRModels/turbulence/PDRkEpsilon/PDRkEpsilon.C b/applications/solvers/combustion/PDRFoam/PDRModels/turbulence/PDRkEpsilon/PDRkEpsilon.C
index eaaafc99d4..5adde282fa 100644
--- a/applications/solvers/combustion/PDRFoam/PDRModels/turbulence/PDRkEpsilon/PDRkEpsilon.C
+++ b/applications/solvers/combustion/PDRFoam/PDRModels/turbulence/PDRkEpsilon/PDRkEpsilon.C
@@ -50,7 +50,7 @@ PDRkEpsilon::PDRkEpsilon
     const volScalarField& rho,
     const volVectorField& U,
     const surfaceScalarField& phi,
-    basicThermo& thermophysicalModel
+    const basicThermo& thermophysicalModel
 )
 :
     RASModel(typeName, rho, U, phi, thermophysicalModel),
diff --git a/applications/solvers/combustion/PDRFoam/PDRModels/turbulence/PDRkEpsilon/PDRkEpsilon.H b/applications/solvers/combustion/PDRFoam/PDRModels/turbulence/PDRkEpsilon/PDRkEpsilon.H
index 0866a28a8e..7a8f7ae54d 100644
--- a/applications/solvers/combustion/PDRFoam/PDRModels/turbulence/PDRkEpsilon/PDRkEpsilon.H
+++ b/applications/solvers/combustion/PDRFoam/PDRModels/turbulence/PDRkEpsilon/PDRkEpsilon.H
@@ -93,7 +93,7 @@ public:
             const volScalarField& rho,
             const volVectorField& U,
             const surfaceScalarField& phi,
-            basicThermo& thermophysicalModel
+            const basicThermo& thermophysicalModel
         );