diff --git a/develop/manuals/meta_manuals/class_manual.cpp b/develop/manuals/meta_manuals/class_manual.cpp
index b46e605..897ab77 100644
--- a/develop/manuals/meta_manuals/class_manual.cpp
+++ b/develop/manuals/meta_manuals/class_manual.cpp
@@ -21,7 +21,7 @@ namespace
     };
 
     class rectangle : public shape {
-        META_HPP_ENABLE_BASE_INFO(shape)
+        META_HPP_ENABLE_POLY_INFO(shape)
     public:
         explicit rectangle(int width, int height)
         : width_{width}
diff --git a/develop/manuals/meta_manuals/uvalue_manual.cpp b/develop/manuals/meta_manuals/uvalue_manual.cpp
index 0a6045f..0abf6c4 100644
--- a/develop/manuals/meta_manuals/uvalue_manual.cpp
+++ b/develop/manuals/meta_manuals/uvalue_manual.cpp
@@ -21,7 +21,7 @@ namespace
     };
 
     class rectangle : public shape {
-        META_HPP_ENABLE_BASE_INFO(shape)
+        META_HPP_ENABLE_POLY_INFO(shape)
     public:
         explicit rectangle(int width, int height)
         : width_{width}
diff --git a/develop/singles/headers/meta.hpp/meta_all.hpp b/develop/singles/headers/meta.hpp/meta_all.hpp
index 71a18d7..4b8c188 100644
--- a/develop/singles/headers/meta.hpp/meta_all.hpp
+++ b/develop/singles/headers/meta.hpp/meta_all.hpp
@@ -2995,7 +2995,7 @@ namespace meta_hpp::detail
             vbases_t vbases{};
             bool is_ambiguous{};
 
-            upcast_func_list_t(const upcast_func_t& in_upcast);
+            explicit upcast_func_list_t(const upcast_func_t& in_upcast);
             upcast_func_list_t(upcasts_t in_upcasts, vbases_t in_vbases);
 
             [[nodiscard]] void* apply(void* ptr) const noexcept;
@@ -8368,17 +8368,18 @@ namespace meta_hpp::detail
                     deep_upcasts_t deep_upcasts;
                 } new_base_data;
 
-                [[maybe_unused]] const auto add_base_class = [&new_base_data]<class_kind Base>(std::in_place_type_t<Base>) {
+                [[maybe_unused]] const auto add_base_class = [&new_base_data]<class_kind Base>() {
                     const class_type& base_class = resolve_type<Base>();
-                    const class_type_data& base_class_data = *type_access(base_class);
+                    const class_type_data& base_data = *type_access(base_class);
 
                     upcast_func_t self_to_base{std::in_place_type<Class>, std::in_place_type<Base>};
+                    upcast_func_list_t self_to_base_list{self_to_base};
 
                     new_base_data.base_classes.emplace_back(base_class);
                     new_base_data.base_upcasts.emplace(base_class, self_to_base);
 
-                    for ( const auto& [deep_class, base_to_deep] : base_class_data.deep_upcasts ) {
-                        upcast_func_list_t self_to_deep = self_to_base + base_to_deep;
+                    for ( const auto& [deep_class, base_to_deep] : base_data.deep_upcasts ) {
+                        upcast_func_list_t self_to_deep = self_to_base_list + base_to_deep;
 
                         const auto& [position, emplaced] = new_base_data.deep_upcasts.try_emplace(
                             deep_class, std::move(self_to_deep)
@@ -8389,9 +8390,9 @@ namespace meta_hpp::detail
                         }
                     }
 
-                    new_base_data.deep_upcasts.emplace(base_class, upcast_func_list_t{self_to_base});
+                    new_base_data.deep_upcasts.emplace(base_class, std::move(self_to_base_list));
                 };
-                (add_base_class(std::in_place_type<type_list_at_t<Is, meta_base_info>>), ...);
+                (add_base_class.template operator()<type_list_at_t<Is, meta_base_info>>(), ...);
 
                 base_classes.swap(new_base_data.base_classes);
                 base_upcasts.swap(new_base_data.base_upcasts);
diff --git a/develop/untests/meta_issues/random_issue_5.cpp b/develop/untests/meta_issues/random_issue_5.cpp
new file mode 100644
index 0000000..1cf8154
--- /dev/null
+++ b/develop/untests/meta_issues/random_issue_5.cpp
@@ -0,0 +1,61 @@
+/*******************************************************************************
+ * This file is part of the "https://github.com/blackmatov/meta.hpp"
+ * For conditions of distribution and use, see copyright notice in LICENSE.md
+ * Copyright (C) 2021-2023, by Matvey Cherevko (blackmatov@gmail.com)
+ ******************************************************************************/
+
+#include <meta.hpp/meta_all.hpp>
+#include <doctest/doctest.h>
+
+namespace
+{
+    struct A1 {};
+    struct B1 : A1 { META_HPP_ENABLE_BASE_INFO(A1) };
+    struct C1 : A1 { META_HPP_ENABLE_BASE_INFO(A1) };
+    struct D1 : B1, C1 { META_HPP_ENABLE_BASE_INFO(B1, C1) };
+    struct E1 : D1 { META_HPP_ENABLE_BASE_INFO(D1) };
+
+    // A1 < B1
+    //        < D1 < E1
+    // A1 < C1
+
+    struct A2 {};
+    struct B2 : virtual A2 { META_HPP_ENABLE_BASE_INFO(A2) };
+    struct C2 : virtual A2 { META_HPP_ENABLE_BASE_INFO(A2) };
+    struct D2 : B2, C2 { META_HPP_ENABLE_BASE_INFO(B2, C2) };
+    struct E2 : D2 { META_HPP_ENABLE_BASE_INFO(D2) };
+
+    // A2 <= B2
+    //         < D2 < E2
+    // A2 <= C2
+}
+
+TEST_CASE("meta/meta_issues/random/5") {
+    namespace meta = meta_hpp;
+
+    {
+        CHECK(meta::is_invocable_with(+[](const A1&){}, B1{}));
+        CHECK(meta::is_invocable_with(+[](const A1&){}, C1{}));
+        CHECK(meta::is_invocable_with(+[](const B1&){}, D1{}));
+        CHECK(meta::is_invocable_with(+[](const C1&){}, D1{}));
+        CHECK(meta::is_invocable_with(+[](const B1&){}, E1{}));
+        CHECK(meta::is_invocable_with(+[](const C1&){}, E1{}));
+        CHECK(meta::is_invocable_with(+[](const D1&){}, E1{}));
+
+        CHECK_FALSE(meta::is_invocable_with(+[](const A1&){}, D1{}));
+        CHECK_FALSE(meta::is_invocable_with(+[](const A1&){}, E1{}));
+    }
+
+    {
+        CHECK(meta::is_invocable_with(+[](const A2&){}, B2{}));
+        CHECK(meta::is_invocable_with(+[](const A2&){}, C2{}));
+        CHECK(meta::is_invocable_with(+[](const B2&){}, D2{}));
+        CHECK(meta::is_invocable_with(+[](const C2&){}, D2{}));
+        CHECK(meta::is_invocable_with(+[](const B2&){}, E2{}));
+        CHECK(meta::is_invocable_with(+[](const C2&){}, E2{}));
+        CHECK(meta::is_invocable_with(+[](const D2&){}, E2{}));
+
+        CHECK(meta::is_invocable_with(+[](const A2&){}, D2{}));
+        CHECK(meta::is_invocable_with(+[](const A2&){}, E2{}));
+    }
+}
diff --git a/headers/meta.hpp/meta_types.hpp b/headers/meta.hpp/meta_types.hpp
index fa10ef7..49523cf 100644
--- a/headers/meta.hpp/meta_types.hpp
+++ b/headers/meta.hpp/meta_types.hpp
@@ -534,7 +534,7 @@ namespace meta_hpp::detail
             vbases_t vbases{};
             bool is_ambiguous{};
 
-            upcast_func_list_t(const upcast_func_t& in_upcast);
+            explicit upcast_func_list_t(const upcast_func_t& in_upcast);
             upcast_func_list_t(upcasts_t in_upcasts, vbases_t in_vbases);
 
             [[nodiscard]] void* apply(void* ptr) const noexcept;
diff --git a/headers/meta.hpp/meta_types/class_type.hpp b/headers/meta.hpp/meta_types/class_type.hpp
index 891d390..e141435 100644
--- a/headers/meta.hpp/meta_types/class_type.hpp
+++ b/headers/meta.hpp/meta_types/class_type.hpp
@@ -37,17 +37,18 @@ namespace meta_hpp::detail
                     deep_upcasts_t deep_upcasts;
                 } new_base_data;
 
-                [[maybe_unused]] const auto add_base_class = [&new_base_data]<class_kind Base>(std::in_place_type_t<Base>) {
+                [[maybe_unused]] const auto add_base_class = [&new_base_data]<class_kind Base>() {
                     const class_type& base_class = resolve_type<Base>();
-                    const class_type_data& base_class_data = *type_access(base_class);
+                    const class_type_data& base_data = *type_access(base_class);
 
                     upcast_func_t self_to_base{std::in_place_type<Class>, std::in_place_type<Base>};
+                    upcast_func_list_t self_to_base_list{self_to_base};
 
                     new_base_data.base_classes.emplace_back(base_class);
                     new_base_data.base_upcasts.emplace(base_class, self_to_base);
 
-                    for ( const auto& [deep_class, base_to_deep] : base_class_data.deep_upcasts ) {
-                        upcast_func_list_t self_to_deep = self_to_base + base_to_deep;
+                    for ( const auto& [deep_class, base_to_deep] : base_data.deep_upcasts ) {
+                        upcast_func_list_t self_to_deep = self_to_base_list + base_to_deep;
 
                         const auto& [position, emplaced] = new_base_data.deep_upcasts.try_emplace(
                             deep_class, std::move(self_to_deep)
@@ -58,9 +59,9 @@ namespace meta_hpp::detail
                         }
                     }
 
-                    new_base_data.deep_upcasts.emplace(base_class, upcast_func_list_t{self_to_base});
+                    new_base_data.deep_upcasts.emplace(base_class, std::move(self_to_base_list));
                 };
-                (add_base_class(std::in_place_type<type_list_at_t<Is, meta_base_info>>), ...);
+                (add_base_class.template operator()<type_list_at_t<Is, meta_base_info>>(), ...);
 
                 base_classes.swap(new_base_data.base_classes);
                 base_upcasts.swap(new_base_data.base_upcasts);