diff --git a/src/optimisation/adjointOptimisation/adjoint/optimisation/adjointSensitivity/incompressible/sensitivitySurface/sensitivitySurfaceIncompressible.C b/src/optimisation/adjointOptimisation/adjoint/optimisation/adjointSensitivity/incompressible/sensitivitySurface/sensitivitySurfaceIncompressible.C
index f6eb845d09..63dbf2d7a4 100644
--- a/src/optimisation/adjointOptimisation/adjoint/optimisation/adjointSensitivity/incompressible/sensitivitySurface/sensitivitySurfaceIncompressible.C
+++ b/src/optimisation/adjointOptimisation/adjoint/optimisation/adjointSensitivity/incompressible/sensitivitySurface/sensitivitySurfaceIncompressible.C
@@ -700,7 +700,7 @@ void sensitivitySurface::accumulateIntegrand(const scalar dt)
     {
         tmp<volTensorField> tgradUa = fvc::grad(Ua);
         const volTensorField::Boundary& gradUabf =
-            tgradUa.ref().boundaryField();
+            tgradUa.cref().boundaryField();
 
         for (const label patchI : sensitivityPatchIDs_)
         {
diff --git a/src/optimisation/adjointOptimisation/adjoint/optimisation/adjointSensitivity/incompressible/sensitivitySurfacePoints/sensitivitySurfacePointsIncompressible.C b/src/optimisation/adjointOptimisation/adjoint/optimisation/adjointSensitivity/incompressible/sensitivitySurfacePoints/sensitivitySurfacePointsIncompressible.C
index 3c9bb45ffc..2d0da2b7f7 100644
--- a/src/optimisation/adjointOptimisation/adjoint/optimisation/adjointSensitivity/incompressible/sensitivitySurfacePoints/sensitivitySurfacePointsIncompressible.C
+++ b/src/optimisation/adjointOptimisation/adjoint/optimisation/adjointSensitivity/incompressible/sensitivitySurfacePoints/sensitivitySurfacePointsIncompressible.C
@@ -513,7 +513,7 @@ void sensitivitySurfacePoints::accumulateIntegrand(const scalar dt)
     {
         tmp<volTensorField> tgradUa = fvc::grad(Ua);
         const volTensorField::Boundary& gradUabf =
-            tgradUa.ref().boundaryField();
+            tgradUa.cref().boundaryField();
         for (const label patchI : sensitivityPatchIDs_)
         {
             const fvPatch& patch = mesh_.boundary()[patchI];
diff --git a/src/optimisation/adjointOptimisation/adjoint/optimisation/adjointSensitivity/incompressible/shapeSensitivities/shapeSensitivitiesIncompressible.C b/src/optimisation/adjointOptimisation/adjoint/optimisation/adjointSensitivity/incompressible/shapeSensitivities/shapeSensitivitiesIncompressible.C
index be4ae28bb5..9f765dbae5 100644
--- a/src/optimisation/adjointOptimisation/adjoint/optimisation/adjointSensitivity/incompressible/shapeSensitivities/shapeSensitivitiesIncompressible.C
+++ b/src/optimisation/adjointOptimisation/adjoint/optimisation/adjointSensitivity/incompressible/shapeSensitivities/shapeSensitivitiesIncompressible.C
@@ -105,7 +105,7 @@ tmp<boundaryVectorField> shapeSensitivities::dvdbMult() const
     const singlePhaseTransportModel& lamTransp = primalVars_.laminarTransport();
     volScalarField nuEff(lamTransp.nu() + turbVars->nutRef());
     tmp<volTensorField> tgradUa = fvc::grad(Ua);
-    const volTensorField::Boundary& gradUabf = tgradUa.ref().boundaryField();
+    const volTensorField::Boundary& gradUabf = tgradUa.cref().boundaryField();
 
     for (const label patchI : sensitivityPatchIDs_)
     {