diff --git a/src/gpu/GridGenerator/grid/BoundaryConditions/BoundaryCondition.h b/src/gpu/GridGenerator/grid/BoundaryConditions/BoundaryCondition.h
index c4f9afac77d78a8d4242b7258bcf932d08b07ec3..28570b46e2bdf92f88cb7696cc7748c767957afb 100644
--- a/src/gpu/GridGenerator/grid/BoundaryConditions/BoundaryCondition.h
+++ b/src/gpu/GridGenerator/grid/BoundaryConditions/BoundaryCondition.h
@@ -119,6 +119,7 @@ public:
     void fillSlipNormalLists()
     {
         for (uint index : this->indices) {
+            (void)index;
             this->normalXList.push_back(normalX);
             this->normalYList.push_back(normalY);
             this->normalZList.push_back(normalZ);