diff --git a/lbmpy_walberla/templates/Boundary.tmpl.h b/lbmpy_walberla/templates/Boundary.tmpl.h
index 6ae98b80750f2e0243170e40a06960c16adffaf8..97dabe87a52bd6b7eb8b3c8116fd0392988528f5 100644
--- a/lbmpy_walberla/templates/Boundary.tmpl.h
+++ b/lbmpy_walberla/templates/Boundary.tmpl.h
@@ -178,7 +178,7 @@ private:
     void run( IBlock * block, IndexVectors::Type type{% if target == 'gpu'%}, cudaStream_t stream = 0 {%endif%});
 
     BlockDataID indexVectorID;
-
+public:
     {{kernel|generate_members(('indexVector', 'indexVectorSize'))|indent(4)}}
 };