diff --git a/src/regionModels/surfaceFilmModels/derivedFvPatchFields/filmHeightInletVelocity/filmHeightInletVelocityFvPatchVectorField.C b/src/regionModels/surfaceFilmModels/derivedFvPatchFields/filmHeightInletVelocity/filmHeightInletVelocityFvPatchVectorField.C
index 148e9d2dc6..3ac7e91792 100644
--- a/src/regionModels/surfaceFilmModels/derivedFvPatchFields/filmHeightInletVelocity/filmHeightInletVelocityFvPatchVectorField.C
+++ b/src/regionModels/surfaceFilmModels/derivedFvPatchFields/filmHeightInletVelocity/filmHeightInletVelocityFvPatchVectorField.C
@@ -123,7 +123,7 @@ void Foam::filmHeightInletVelocityFvPatchVectorField::updateCoeffs()
     const fvPatchField<scalar>& deltafp =
         patch().lookupPatchField<volScalarField, scalar>(deltafName_);
 
-    vectorField n = patch().nf();
+    const vectorField& n = patch().nf();
     const scalarField& magSf = patch().magSf();
 
     operator==(deltafp*n*phip/(rhop*magSf*sqr(deltafp) + ROOTVSMALL));