diff --git a/untests/meta_states/metadata_tests.cpp b/untests/meta_states/metadata_tests.cpp
index 9a8720a..04e59eb 100644
--- a/untests/meta_states/metadata_tests.cpp
+++ b/untests/meta_states/metadata_tests.cpp
@@ -286,12 +286,12 @@ TEST_CASE("meta/meta_states/metadata/other") {
     }
 
     SUBCASE("nullptr") {
-        meta::nullptr_<nullptr_t>({
+        meta::nullptr_<std::nullptr_t>({
             .metadata{
                 {"desc", meta::uvalue{"nullptr_t"s}}
             }
         });
-        CHECK(meta::resolve_type<nullptr_t>().get_metadata().at("desc") == "nullptr_t"s);
+        CHECK(meta::resolve_type<std::nullptr_t>().get_metadata().at("desc") == "nullptr_t"s);
     }
 
     SUBCASE("number") {
diff --git a/untests/meta_utilities/arg6_tests.cpp b/untests/meta_utilities/arg6_tests.cpp
index 5b32f2e..65dba9e 100644
--- a/untests/meta_utilities/arg6_tests.cpp
+++ b/untests/meta_utilities/arg6_tests.cpp
@@ -9,6 +9,8 @@
 namespace
 {
     struct base {
+        base() = default;
+        base(const base&) = default;
         virtual ~base() = default;
         virtual int int_method() const = 0;
     };