diff --git a/src/immersedBoundary/immersedBoundaryDynamicMesh/refineImmersedBoundaryMesh/refineImmersedBoundaryMesh.C b/src/immersedBoundary/immersedBoundaryDynamicMesh/refineImmersedBoundaryMesh/refineImmersedBoundaryMesh.C
index 1eaf4a209..1be78870d 100644
--- a/src/immersedBoundary/immersedBoundaryDynamicMesh/refineImmersedBoundaryMesh/refineImmersedBoundaryMesh.C
+++ b/src/immersedBoundary/immersedBoundaryDynamicMesh/refineImmersedBoundaryMesh/refineImmersedBoundaryMesh.C
@@ -321,6 +321,7 @@ Foam::refineImmersedBoundaryMesh::refinementCells
         case IB_CELL_CELLS:
         {
             addIbCellCells(refCellSet);
+            [[fallthrough]];
         }
 
         case IB_CELLS: