diff --git a/test/sources/LibcxxTester.h b/test/sources/LibcxxTester.h
index a1dad65c..aa05884c 100644
--- a/test/sources/LibcxxTester.h
+++ b/test/sources/LibcxxTester.h
@@ -14,6 +14,7 @@
 
 #include "libcxx/Support.h"
 
+#include "../../include/momo/Version.h"
 #include "../../include/momo/ObjectManager.h"
 
 #include <iostream>
diff --git a/test/sources/libcxx/Support.h b/test/sources/libcxx/Support.h
index 1f3d94e5..2ed1dd42 100644
--- a/test/sources/libcxx/Support.h
+++ b/test/sources/libcxx/Support.h
@@ -15,11 +15,14 @@
 #include <cfloat>
 #include <string>
 #include <cmath>
+#include <optional>
 
 //#define LIBCPP_HAS_BAD_NEWS_FOR_MOMO
 
 #define TEST_STD_VER 20
 
+#undef _LIBCPP_VERSION	//?
+
 #include "support/test_macros.h"
 
 #include "support/MoveOnly.h"
diff --git a/test/sources/libcxx/map/map.cons/deduct.pass.cpp b/test/sources/libcxx/map/map.cons/deduct.pass.cpp
index 45bc2d9b..5fea49f2 100644
--- a/test/sources/libcxx/map/map.cons/deduct.pass.cpp
+++ b/test/sources/libcxx/map/map.cons/deduct.pass.cpp
@@ -150,13 +150,17 @@ int main(int, char**)
     ASSERT_SAME_TYPE(decltype(m1), momo::stdish::map<int, int>);
 
 #if !defined(TEST_GCC) && !defined(TEST_CLANG)
+#if MOMO_VERSION_MAJOR > 3
     using value_type = std::pair<const int, int>;
     momo::stdish::map m2{{value_type{1, 2}, {3, 4}}, std::less<int>()};
     ASSERT_SAME_TYPE(decltype(m2), momo::stdish::map<int, int>);
+#endif
 #endif
     }
 
+#if MOMO_VERSION_MAJOR > 3
     AssociativeContainerDeductionGuidesSfinaeAway<momo::stdish::map, momo::stdish::map<int, long>>();
+#endif
 
     return 0;
 }
diff --git a/test/sources/libcxx/map/map.cons/deduct_const.pass.cpp b/test/sources/libcxx/map/map.cons/deduct_const.pass.cpp
index c2cd2723..1defd0a3 100644
--- a/test/sources/libcxx/map/map.cons/deduct_const.pass.cpp
+++ b/test/sources/libcxx/map/map.cons/deduct_const.pass.cpp
@@ -74,6 +74,7 @@ int main(int, char**)
     assert(std::equal(m.begin(), m.end(), std::begin(expected_m), std::end(expected_m)));
     }
 
+#if MOMO_VERSION_MAJOR > 3
     {
     momo::stdish::map m({ PC{1,1L}, PC{2,2L}, PC{1,1L}, PC{INT_MAX,1L}, PC{3,1L} }, std::greater<int>());
 
@@ -81,6 +82,7 @@ int main(int, char**)
     const PC expected_m[] = { {INT_MAX,1L}, {3,1L}, {2,2L}, {1, 1L} };
     assert(std::equal(m.begin(), m.end(), std::begin(expected_m), std::end(expected_m)));
     }
+#endif
 
     {
     momo::stdish::map m({ PC{1,1L}, PC{2,2L}, PC{1,1L}, PC{INT_MAX,1L}, PC{3,1L} }, std::greater<int>(), test_allocator<PC>(0, 43));
@@ -91,6 +93,7 @@ int main(int, char**)
     assert(m.get_allocator().get_id() == 43);
     }
 
+#if MOMO_VERSION_MAJOR > 3
     {
     momo::stdish::map m({ PC{1,1L}, PC{2,2L}, PC{1,1L}, PC{INT_MAX,1L}, PC{3,1L} }, test_allocator<PC>(0, 45));
 
@@ -99,6 +102,7 @@ int main(int, char**)
     assert(std::equal(m.begin(), m.end(), std::begin(expected_m), std::end(expected_m)));
     assert(m.get_allocator().get_id() == 45);
     }
+#endif
 #endif
 
     return 0;
diff --git a/test/sources/libcxx/multimap/multimap.cons/deduct.pass.cpp b/test/sources/libcxx/multimap/multimap.cons/deduct.pass.cpp
index 223ecadd..1b5f3c1e 100644
--- a/test/sources/libcxx/multimap/multimap.cons/deduct.pass.cpp
+++ b/test/sources/libcxx/multimap/multimap.cons/deduct.pass.cpp
@@ -150,13 +150,17 @@ int main(int, char**)
     ASSERT_SAME_TYPE(decltype(m1), momo::stdish::multimap<int, int>);
 
 #if !defined(TEST_GCC) && !defined(TEST_CLANG)
+#if MOMO_VERSION_MAJOR > 3
     using value_type = std::pair<const int, int>;
     momo::stdish::multimap m2{{value_type{1, 2}, {3, 4}}, std::less<int>()};
     ASSERT_SAME_TYPE(decltype(m2), momo::stdish::multimap<int, int>);
+#endif
 #endif
     }
 
+#if MOMO_VERSION_MAJOR > 3
     AssociativeContainerDeductionGuidesSfinaeAway<momo::stdish::multimap, momo::stdish::multimap<int, long>>();
+#endif
 
     return 0;
 }
diff --git a/test/sources/libcxx/multimap/multimap.cons/deduct_const.pass.cpp b/test/sources/libcxx/multimap/multimap.cons/deduct_const.pass.cpp
index 06df26e0..f66ae08d 100644
--- a/test/sources/libcxx/multimap/multimap.cons/deduct_const.pass.cpp
+++ b/test/sources/libcxx/multimap/multimap.cons/deduct_const.pass.cpp
@@ -74,6 +74,7 @@ int main(int, char**)
     assert(std::equal(m.begin(), m.end(), std::begin(expected_m), std::end(expected_m)));
     }
 
+#if MOMO_VERSION_MAJOR > 3
     {
     momo::stdish::multimap m({ PC{1,1L}, PC{2,2L}, PC{1,1L}, PC{INT_MAX,1L}, PC{3,1L} }, std::greater<int>());
 
@@ -81,6 +82,7 @@ int main(int, char**)
     const PC expected_m[] = { {INT_MAX,1L}, {3,1L}, {2,2L}, {1,1L}, {1,1L} };
     assert(std::equal(m.begin(), m.end(), std::begin(expected_m), std::end(expected_m)));
     }
+#endif
 
     {
     momo::stdish::multimap m({ PC{1,1L}, PC{2,2L}, PC{1,1L}, PC{INT_MAX,1L}, PC{3,1L} }, std::greater<int>(), test_allocator<PC>(0, 43));
@@ -91,6 +93,7 @@ int main(int, char**)
     assert(m.get_allocator().get_id() == 43);
     }
 
+#if MOMO_VERSION_MAJOR > 3
     {
     momo::stdish::multimap m({ PC{1,1L}, PC{2,2L}, PC{1,1L}, PC{INT_MAX,1L}, PC{3,1L} }, test_allocator<PC>(0, 45));
 
@@ -99,6 +102,7 @@ int main(int, char**)
     assert(std::equal(m.begin(), m.end(), std::begin(expected_m), std::end(expected_m)));
     assert(m.get_allocator().get_id() == 45);
     }
+#endif
 #endif
 
     return 0;
diff --git a/test/sources/libcxx/set/set.cons/deduct.pass.cpp b/test/sources/libcxx/set/set.cons/deduct.pass.cpp
index 4857f171..9fceffe5 100644
--- a/test/sources/libcxx/set/set.cons/deduct.pass.cpp
+++ b/test/sources/libcxx/set/set.cons/deduct.pass.cpp
@@ -179,7 +179,9 @@ int main(int, char **) {
     assert(s.size() == 2);
   }
 
+#if MOMO_VERSION_MAJOR > 3
   AssociativeContainerDeductionGuidesSfinaeAway<momo::stdish::set, momo::stdish::set<int>>();
+#endif
 
   return 0;
 }
diff --git a/test/sources/libcxx/unord.map/unord.map.cnstr/deduct.pass.cpp b/test/sources/libcxx/unord.map/unord.map.cnstr/deduct.pass.cpp
index 778a1d7c..4eaa1bd5 100644
--- a/test/sources/libcxx/unord.map/unord.map.cnstr/deduct.pass.cpp
+++ b/test/sources/libcxx/unord.map/unord.map.cnstr/deduct.pass.cpp
@@ -218,7 +218,9 @@ int main(int, char**)
     ASSERT_SAME_TYPE(decltype(m2), momo::stdish::unordered_map<int, int>);
     }
 
+#if MOMO_VERSION_MAJOR > 3
     UnorderedContainerDeductionGuidesSfinaeAway<momo::stdish::unordered_map, momo::stdish::unordered_map<int, long>>();
+#endif
 
     return 0;
 }
diff --git a/test/sources/libcxx/unord.map/unord.map.cnstr/deduct_const.pass.cpp b/test/sources/libcxx/unord.map/unord.map.cnstr/deduct_const.pass.cpp
index d85d2baa..5a0fc670 100644
--- a/test/sources/libcxx/unord.map/unord.map.cnstr/deduct_const.pass.cpp
+++ b/test/sources/libcxx/unord.map/unord.map.cnstr/deduct_const.pass.cpp
@@ -114,6 +114,7 @@ int main(int, char**)
     assert(std::is_permutation(m.begin(), m.end(), std::begin(expected_m), std::end(expected_m)));
     }
 
+#if MOMO_VERSION_MAJOR > 3
     {
     momo::stdish::unordered_map m({ PC{1,1L}, PC{2,2L}, PC{1,1L}, PC{INT_MAX,1L}, PC{3,1L} }, 42, std::hash<long long>());
     ASSERT_SAME_TYPE(decltype(m), momo::stdish::unordered_map<int, long, std::hash<long long>>);
@@ -125,6 +126,7 @@ int main(int, char**)
     ASSERT_SAME_TYPE(decltype(m), momo::stdish::unordered_map<int, long, std::hash<long long>, std::equal_to<>>);
     assert(std::is_permutation(m.begin(), m.end(), std::begin(expected_m), std::end(expected_m)));
     }
+#endif
 
     {
     momo::stdish::unordered_map m({ PC{1,1L}, PC{2,2L}, PC{1,1L}, PC{INT_MAX,1L}, PC{3,1L} }, 42, std::hash<long long>(), std::equal_to<>(), test_allocator<PC>(0, 44));
@@ -149,6 +151,7 @@ int main(int, char**)
     assert(m.get_allocator().get_id() == 46);
     }
 
+#if MOMO_VERSION_MAJOR > 3
     {
     momo::stdish::unordered_map m({ PC{1,1L}, PC{2,2L}, PC{1,1L}, PC{INT_MAX,1L}, PC{3,1L} }, 42, test_allocator<PC>(0, 47));
     ASSERT_SAME_TYPE(decltype(m), momo::stdish::unordered_map<int, long, momo::HashCoder<int>, std::equal_to<int>, test_allocator<PC>>);
@@ -162,6 +165,7 @@ int main(int, char**)
     assert(std::is_permutation(m.begin(), m.end(), std::begin(expected_m), std::end(expected_m)));
     assert(m.get_allocator().get_id() == 48);
     }
+#endif
 
     return 0;
 }
diff --git a/test/sources/libcxx/unord.multimap/unord.multimap.cnstr/deduct.pass.cpp b/test/sources/libcxx/unord.multimap/unord.multimap.cnstr/deduct.pass.cpp
index 87b28147..be7bc0ae 100644
--- a/test/sources/libcxx/unord.multimap/unord.multimap.cnstr/deduct.pass.cpp
+++ b/test/sources/libcxx/unord.multimap/unord.multimap.cnstr/deduct.pass.cpp
@@ -218,7 +218,9 @@ int main(int, char**)
     ASSERT_SAME_TYPE(decltype(m2), momo::stdish::unordered_multimap<int, int>);
     }
 
+#if MOMO_VERSION_MAJOR > 3
     UnorderedContainerDeductionGuidesSfinaeAway<momo::stdish::unordered_multimap, momo::stdish::unordered_multimap<int, long>>();
+#endif
 
     return 0;
 }
diff --git a/test/sources/libcxx/unord.multimap/unord.multimap.cnstr/deduct_const.pass.cpp b/test/sources/libcxx/unord.multimap/unord.multimap.cnstr/deduct_const.pass.cpp
index 471aaddc..894d4b54 100644
--- a/test/sources/libcxx/unord.multimap/unord.multimap.cnstr/deduct_const.pass.cpp
+++ b/test/sources/libcxx/unord.multimap/unord.multimap.cnstr/deduct_const.pass.cpp
@@ -114,6 +114,7 @@ int main(int, char**)
     assert(std::is_permutation(m.begin(), m.end(), std::begin(expected_m), std::end(expected_m)));
     }
 
+#if MOMO_VERSION_MAJOR > 3
     {
     momo::stdish::unordered_multimap m({ PC{1,1L}, PC{2,2L}, PC{1,1L}, PC{INT_MAX,1L}, PC{3,1L} }, 42, std::hash<long long>());
     ASSERT_SAME_TYPE(decltype(m), momo::stdish::unordered_multimap<int, long, std::hash<long long>>);
@@ -125,6 +126,7 @@ int main(int, char**)
     ASSERT_SAME_TYPE(decltype(m), momo::stdish::unordered_multimap<int, long, std::hash<long long>, std::equal_to<>>);
     assert(std::is_permutation(m.begin(), m.end(), std::begin(expected_m), std::end(expected_m)));
     }
+#endif
 
     {
     momo::stdish::unordered_multimap m({ PC{1,1L}, PC{2,2L}, PC{1,1L}, PC{INT_MAX,1L}, PC{3,1L} }, 42, std::hash<long long>(), std::equal_to<>(), test_allocator<PC>(0, 44));
@@ -149,6 +151,7 @@ int main(int, char**)
     assert(m.get_allocator().get_id() == 46);
     }
 
+#if MOMO_VERSION_MAJOR > 3
     {
     momo::stdish::unordered_multimap m({ PC{1,1L}, PC{2,2L}, PC{1,1L}, PC{INT_MAX,1L}, PC{3,1L} }, 42, test_allocator<PC>(0, 47));
     ASSERT_SAME_TYPE(decltype(m), momo::stdish::unordered_multimap<int, long, momo::HashCoder<int>, std::equal_to<int>, test_allocator<PC>>);
@@ -162,6 +165,7 @@ int main(int, char**)
     assert(std::is_permutation(m.begin(), m.end(), std::begin(expected_m), std::end(expected_m)));
     assert(m.get_allocator().get_id() == 48);
     }
+#endif
 
     return 0;
 }
diff --git a/test/sources/libcxx/unord.set/unord.set.cnstr/deduct.pass.cpp b/test/sources/libcxx/unord.set/unord.set.cnstr/deduct.pass.cpp
index 2516da74..536968d4 100644
--- a/test/sources/libcxx/unord.set/unord.set.cnstr/deduct.pass.cpp
+++ b/test/sources/libcxx/unord.set/unord.set.cnstr/deduct.pass.cpp
@@ -189,7 +189,9 @@ int main(int, char**)
     }
 
 #if !(defined(TEST_MSVC) && _MSC_VER < 1930) && !(defined(TEST_GCC) && __GNUC__ < 11)
+#if MOMO_VERSION_MAJOR > 3
     UnorderedContainerDeductionGuidesSfinaeAway<std::unordered_set, std::unordered_set<int>>();
+#endif
 #endif
 
     return 0;
diff --git a/test/sources/libcxx/vector/vector.cons/deduct.pass.cpp b/test/sources/libcxx/vector/vector.cons/deduct.pass.cpp
index 6367a816..01e068a9 100644
--- a/test/sources/libcxx/vector/vector.cons/deduct.pass.cpp
+++ b/test/sources/libcxx/vector/vector.cons/deduct.pass.cpp
@@ -149,7 +149,9 @@ TEST_CONSTEXPR_CXX20 bool tests() {
         }
     }
 
+#if MOMO_VERSION_MAJOR > 3
     SequenceContainerDeductionGuidesSfinaeAway<momo::stdish::vector, momo::stdish::vector<int>>();
+#endif
 
     return true;
 }
diff --git a/test/sources/libcxx/vector/vector.cons/move_assign_noexcept.pass.cpp b/test/sources/libcxx/vector/vector.cons/move_assign_noexcept.pass.cpp
index 6c5b5dba..e0e29f10 100644
--- a/test/sources/libcxx/vector/vector.cons/move_assign_noexcept.pass.cpp
+++ b/test/sources/libcxx/vector/vector.cons/move_assign_noexcept.pass.cpp
@@ -88,10 +88,12 @@ int main(int, char**)
         typedef std::vector<MoveOnly, some_alloc2<MoveOnly>> C;
         static_assert( std::is_nothrow_move_assignable<C>::value, "");
     }
+#if MOMO_VERSION_MAJOR > 3
     {  // POCMA false, is_always_equal false
         typedef std::vector<MoveOnly, some_alloc3<MoveOnly>> C;
         static_assert(!std::is_nothrow_move_assignable<C>::value, "");
     }
+#endif
 #endif
 
     return 0;