diff --git a/src/ThermophysicalTransportModels/laminar/unityLewisFourier/unityLewisFourier.H b/src/ThermophysicalTransportModels/laminar/unityLewisFourier/unityLewisFourier.H
index 0ea76e041b..29abda7c0c 100644
--- a/src/ThermophysicalTransportModels/laminar/unityLewisFourier/unityLewisFourier.H
+++ b/src/ThermophysicalTransportModels/laminar/unityLewisFourier/unityLewisFourier.H
@@ -113,7 +113,7 @@ public:
             return volScalarField::New
             (
                 "DEff",
-                this->alphaEff()
+                this->thermo().alpha()
             );
         }
 
@@ -125,7 +125,7 @@ public:
             const label patchi
         ) const
         {
-            return this->alphaEff(patchi);
+            return this->thermo().alpha(patchi);
         }
 
         //- Return the heat flux [W/m^2]
diff --git a/src/ThermophysicalTransportModels/turbulence/unityLewisEddyDiffusivity/unityLewisEddyDiffusivity.H b/src/ThermophysicalTransportModels/turbulence/unityLewisEddyDiffusivity/unityLewisEddyDiffusivity.H
index 28932b46f7..05a461ec4f 100644
--- a/src/ThermophysicalTransportModels/turbulence/unityLewisEddyDiffusivity/unityLewisEddyDiffusivity.H
+++ b/src/ThermophysicalTransportModels/turbulence/unityLewisEddyDiffusivity/unityLewisEddyDiffusivity.H
@@ -185,7 +185,7 @@ public:
             return volScalarField::New
             (
                 "DEff",
-                alphaEff()
+                this->thermo().alpha() + alphat()
             );
         }
 
@@ -197,7 +197,7 @@ public:
             const label patchi
         ) const
         {
-            return alphaEff(patchi);
+            return this->thermo().alpha(patchi) + alphat(patchi);
         }
 
         //- Return the heat flux [W/m^2]