diff --git a/src/regionModels/surfaceFilmModels/kinematicSingleLayer/kinematicSingleLayer.C b/src/regionModels/surfaceFilmModels/kinematicSingleLayer/kinematicSingleLayer.C
index 2bba3bd5d3..02dce3f268 100644
--- a/src/regionModels/surfaceFilmModels/kinematicSingleLayer/kinematicSingleLayer.C
+++ b/src/regionModels/surfaceFilmModels/kinematicSingleLayer/kinematicSingleLayer.C
@@ -936,6 +936,12 @@ const volVectorField& kinematicSingleLayer::Uw() const
 }
 
 
+const volScalarField& kinematicSingleLayer::deltaRho() const
+{
+    return deltaRho_;
+}
+
+
 const surfaceScalarField& kinematicSingleLayer::phi() const
 {
     return phi_;
diff --git a/src/regionModels/surfaceFilmModels/kinematicSingleLayer/kinematicSingleLayer.H b/src/regionModels/surfaceFilmModels/kinematicSingleLayer/kinematicSingleLayer.H
index 81ea960d89..2dbdaac6d7 100644
--- a/src/regionModels/surfaceFilmModels/kinematicSingleLayer/kinematicSingleLayer.H
+++ b/src/regionModels/surfaceFilmModels/kinematicSingleLayer/kinematicSingleLayer.H
@@ -351,6 +351,9 @@ public:
             //- Return the film wall velocity [m/s]
             virtual const volVectorField& Uw() const;
 
+            //- Return the film thickness*density (helper field) [kg/m3]
+            virtual const volScalarField& deltaRho() const;
+
             //- Return the film flux [kg.m/s]
             virtual const surfaceScalarField& phi() const;