diff --git a/src/regionModels/thermoBaffleModels/thermoBaffle2D/thermoBaffle2DI.H b/src/regionModels/thermoBaffleModels/thermoBaffle2D/thermoBaffle2DI.H
index 2324f0534a..0e3978da3c 100644
--- a/src/regionModels/thermoBaffleModels/thermoBaffle2D/thermoBaffle2DI.H
+++ b/src/regionModels/thermoBaffleModels/thermoBaffle2D/thermoBaffle2DI.H
@@ -50,7 +50,7 @@ inline tmp<scalarField> thermoBaffle2D::hs
     const label patchI
 ) const
 {
-    const scalarField& Cp = thermo_->Cp()().boundaryField()[patchI];
+    const scalarField Cp(thermo_->Cp(patchI));
     return Cp*(T - 298.15);
 }