diff --git a/src/mesh/snappyHexMesh/meshRefinement/meshRefinementProblemCells.C b/src/mesh/snappyHexMesh/meshRefinement/meshRefinementProblemCells.C
index ffd42013dc3244d9f84e3c2f8afa6bfab5e1bb06..78c39347521e3a03dcbd28f5e2544a7c47108119 100644
--- a/src/mesh/snappyHexMesh/meshRefinement/meshRefinementProblemCells.C
+++ b/src/mesh/snappyHexMesh/meshRefinement/meshRefinementProblemCells.C
@@ -817,7 +817,7 @@ Foam::labelList Foam::meshRefinement::markFacesOnProblemCells
                 }
             }
         }
-        else if (nBoundaryAnchors == 7)
+        else if (nBoundaryAnchors == 7 && nonBoundaryAnchor != -1)
         {
             // Mark the cell. Store the (single!) non-boundary anchor point.
             hasSevenBoundaryAnchorPoints.set(celli, 1u);