diff --git a/dune/gdt/test/instationary-eocstudies/base.hh b/dune/gdt/test/instationary-eocstudies/base.hh
index 28136a53fd20e40cba355aa1f7be70945e52ea06..874a035d2be31bc75386e80fedae97d4005ba5d1 100644
--- a/dune/gdt/test/instationary-eocstudies/base.hh
+++ b/dune/gdt/test/instationary-eocstudies/base.hh
@@ -300,8 +300,8 @@ protected:
   }
 
   double T_end_;
-  const size_t num_refinements_;
-  const size_t num_additional_refinements_for_reference_;
+  size_t num_refinements_;
+  size_t num_additional_refinements_for_reference_;
   const std::function<void(const DiscreteBochnerFunction<V, GV, m>&, const std::string&)> visualize_;
   size_t current_refinement_;
   std::map<std::string, std::map<std::string, double>> current_data_;