diff --git a/exercises/exercise-biomineralization/biominspatialparams.hh b/exercises/exercise-biomineralization/biominspatialparams.hh
index 06c7c5cf7f3fdff9e56eb26ad7e092ab45122d30..263042195b6d29e031be13b6d16461cf5901dc52 100644
--- a/exercises/exercise-biomineralization/biominspatialparams.hh
+++ b/exercises/exercise-biomineralization/biominspatialparams.hh
@@ -48,7 +48,7 @@ class BioMinSpatialparams
 
     using GridView = typename GridGeometry::GridView;
     using CoordScalar = typename GridView::ctype;
-    enum { dimWorld=GridView::dimensionworld };
+    static constexpr int dimWorld = GridView::dimensionworld;
     using Element = typename GridView::template Codim<0>::Entity;
 
     using GlobalPosition = Dune::FieldVector<CoordScalar, dimWorld>;
diff --git a/exercises/solution/exercise-biomineralization/biominspatialparams.hh b/exercises/solution/exercise-biomineralization/biominspatialparams.hh
index 06c7c5cf7f3fdff9e56eb26ad7e092ab45122d30..263042195b6d29e031be13b6d16461cf5901dc52 100644
--- a/exercises/solution/exercise-biomineralization/biominspatialparams.hh
+++ b/exercises/solution/exercise-biomineralization/biominspatialparams.hh
@@ -48,7 +48,7 @@ class BioMinSpatialparams
 
     using GridView = typename GridGeometry::GridView;
     using CoordScalar = typename GridView::ctype;
-    enum { dimWorld=GridView::dimensionworld };
+    static constexpr int dimWorld = GridView::dimensionworld;
     using Element = typename GridView::template Codim<0>::Entity;
 
     using GlobalPosition = Dune::FieldVector<CoordScalar, dimWorld>;