diff --git a/Src/LinearSolvers/MLMG/AMReX_MLCellABecLap.H b/Src/LinearSolvers/MLMG/AMReX_MLCellABecLap.H
index 5b60fb7853..9c2e936d38 100644
--- a/Src/LinearSolvers/MLMG/AMReX_MLCellABecLap.H
+++ b/Src/LinearSolvers/MLMG/AMReX_MLCellABecLap.H
@@ -43,6 +43,23 @@ public:
         return m_overset_mask[amrlev][mglev].get();
     }
 
+    void setOversetMask(int amrlev, const iMultiFab& a_mask)
+    {
+#ifdef AMREX_USE_OMP
+#pragma omp parallel if(Gpu::notInLaunchRegion())
+#endif
+        for (MFIter mfi(*m_overset_mask[amrlev][0], TilingIfNotGPU());mfi.isValid();++mfi)
+        {
+            Array4<int const> const& amsk = a_mask.const_array(mfi);
+            Array4<int> const& omsk = m_overset_mask[amrlev][0]->array(mfi);
+            Box const& bx = mfi.tilebox();
+            AMREX_HOST_DEVICE_PARALLEL_FOR_3D(bx,i,j,k,
+            {
+                omsk(i,j,k) = 1-amsk(i,j,k);
+            });
+        }
+    }
+
     [[nodiscard]] bool needsUpdate () const override {
         return MLCellLinOpT<MF>::needsUpdate();
     }