diff --git a/dune/multimesh/mmhierarchiciterator.hh b/dune/multimesh/mmhierarchiciterator.hh
index 80212437fce8e316f57d26ab81910fa3dec96663..9981f34d4740e2123b3b441b7ea250e87bb3bcd5 100644
--- a/dune/multimesh/mmhierarchiciterator.hh
+++ b/dune/multimesh/mmhierarchiciterator.hh
@@ -5,7 +5,6 @@
 
 #include <numeric>
 #include <stack>
-#include <variant>
 
 #include <dune/common/iteratorfacades.hh>
 #include <dune/common/iteratorrange.hh>
diff --git a/src/CMakeLists.txt b/src/CMakeLists.txt
index a67b834d49f79a32f633e6cd2a973b87a8130d83..33225dc64506776fe597653b10922e9342bdd5f4 100644
--- a/src/CMakeLists.txt
+++ b/src/CMakeLists.txt
@@ -40,27 +40,12 @@ if (dune-functions_FOUND AND dune-alugrid_FOUND AND HAVE_ALBERTA)
 
   find_package(MTL QUIET PATHS /opt/development/mtl4)
   if (MTL_FOUND)
-    set(CXX_ELEVEN_FEATURE_LIST "MOVE" "AUTO" "RANGEDFOR" "INITLIST" "STATICASSERT" "DEFAULTIMPL")
-    set(MTL_COMPILE_DEFINITIONS "")
-    foreach(feature ${CXX_ELEVEN_FEATURE_LIST})
-      list(APPEND MTL_COMPILE_DEFINITIONS "MTL_WITH_${feature}")
-    endforeach()
-
-    if (HAVE_UMFPACK OR ENABLE_SUITESPARSE OR SuiteSparse_FOUND)
-      list(APPEND MTL_COMPILE_DEFINITIONS "MTL_HAS_UMFPACK")
-    endif ()
-
-    set(MTL_TARGETS "")
-    list(APPEND MTL_TARGETS "phasefield" "phasefield2" "phasefield3" "phasefield4")
-
-    foreach(target ${MTL_TARGETS})
+    foreach(target "phasefield" "phasefield2" "phasefield3" "phasefield4")
       add_executable(${target} ${target}.cc)
       target_link_dune_default_libraries(${target})
       add_dune_alberta_flags(GRIDDIM 2 WORLDDIM 2 ${target})
       target_include_directories(${target} PRIVATE ${MTL_INCLUDE_DIRS})
       target_compile_definitions(${target} PRIVATE ${MTL_COMPILE_DEFINITIONS})
-      target_compile_options(${target} PRIVATE -Wno-deprecated-declarations)
     endforeach()
-
-  endif ()
+  endif (MTL_FOUND)
 endif ()
\ No newline at end of file
diff --git a/src/interpolation.hh b/src/interpolation.hh
index 63da9f9c077ca913822eba7db295b1c737f665d5..e0022a1f081de54fbb4cfc6bad325e7999d8ba4a 100644
--- a/src/interpolation.hh
+++ b/src/interpolation.hh
@@ -57,7 +57,7 @@ namespace Dune
           auto oldSubLocalView = Dune::Functions::subspaceBasis(oldBasis, treePath).localView();
           auto newSubLocalView = Dune::Functions::subspaceBasis(newBasis, treePath).localView();
 
-          interpolate(oldCoeff, oldEntity, oldSubLocalView, newCoeff, newEntity, newSubLocalView);
+          this->interpolate(oldCoeff, oldEntity, oldSubLocalView, newCoeff, newEntity, newSubLocalView);
         });
       }
     }
diff --git a/test/CMakeLists.txt b/test/CMakeLists.txt
index c086a040aa53ffb7f3b67d02ae11db85d6620395..2e6106f04785ea3273b023764e50cb39ac767f83 100644
--- a/test/CMakeLists.txt
+++ b/test/CMakeLists.txt
@@ -1,4 +1,7 @@
 dune_add_test(SOURCES testvolume.cc)
 dune_add_test(SOURCES testnumentities.cc)
 dune_add_test(SOURCES testtransform.cc)
-dune_add_test(SOURCES testgridviews.cc)
\ No newline at end of file
+
+if (DUNE_HAVE_CXX_VARIANT)
+  dune_add_test(SOURCES testgridviews.cc)
+endif (DUNE_HAVE_CXX_VARIANT)
\ No newline at end of file