diff --git a/CMakeLists.txt b/CMakeLists.txt
index 5cd3aa10..7c207d03 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -25,11 +25,6 @@ set(CMAKE_CXX_STANDARD 17)
 set(CMAKE_CXX_STANDARD_REQUIRED ON)
 set(CMAKE_CXX_EXTENSIONS OFF)
 
-if(APPLE)
-    set(CMAKE_CXX_STANDARD_INCLUDE_DIRECTORIES
-            ${CMAKE_CXX_IMPLICIT_INCLUDE_DIRECTORIES})
-endif(APPLE)
-
 #
 # clang-uml custom defines
 #
@@ -124,6 +119,11 @@ else()
     message(STATUS "Found LibTooling libraries: ${LIBTOOLING_LIBS}")
 endif()
 
+if(APPLE OR (LLVM_VERSION_MAJOR GREATER_EQUAL 16))
+    set(CMAKE_CXX_STANDARD_INCLUDE_DIRECTORIES
+            ${CMAKE_CXX_IMPLICIT_INCLUDE_DIRECTORIES})
+endif()
+
 #
 # Setup threads library
 #
diff --git a/src/class_diagram/model/class_element.cc b/src/class_diagram/model/class_element.cc
index f449e49e..0d1ab1a3 100644
--- a/src/class_diagram/model/class_element.cc
+++ b/src/class_diagram/model/class_element.cc
@@ -34,8 +34,12 @@ common::model::access_t class_element::access() const { return access_; }
 
 std::string class_element::name() const { return name_; }
 
+void class_element::set_name(const std::string &name) { name_ = name; }
+
 std::string class_element::type() const { return type_; }
 
+void class_element::set_type(const std::string &type) { type_ = type; }
+
 inja::json class_element::context() const
 {
     inja::json ctx;
diff --git a/src/class_diagram/model/class_element.h b/src/class_diagram/model/class_element.h
index d4161278..897158e8 100644
--- a/src/class_diagram/model/class_element.h
+++ b/src/class_diagram/model/class_element.h
@@ -36,7 +36,10 @@ public:
 
     common::model::access_t access() const;
     std::string name() const;
+    void set_name(const std::string &name);
+
     std::string type() const;
+    void set_type(const std::string &type);
 
     virtual inja::json context() const;
 
diff --git a/src/class_diagram/visitor/translation_unit_visitor.cc b/src/class_diagram/visitor/translation_unit_visitor.cc
index 549bc9aa..7a583572 100644
--- a/src/class_diagram/visitor/translation_unit_visitor.cc
+++ b/src/class_diagram/visitor/translation_unit_visitor.cc
@@ -986,10 +986,13 @@ bool translation_unit_visitor::process_template_parameters(
             const auto *template_nontype_parameter =
                 clang::dyn_cast_or_null<clang::NonTypeTemplateParmDecl>(
                     parameter);
+
             std::optional<std::string> default_arg;
+
             if (template_nontype_parameter->hasDefaultArgument())
                 default_arg = common::to_string(
                     template_nontype_parameter->getDefaultArgument());
+
             auto ct = template_parameter::make_non_type_template(
                 template_nontype_parameter->getType().getAsString(),
                 template_nontype_parameter->getNameAsString(), default_arg,
@@ -1082,6 +1085,7 @@ void translation_unit_visitor::process_class_bases(
         if (const auto *record_type =
                 base.getType()->getAs<clang::RecordType>();
             record_type != nullptr) {
+            cp.set_name(record_type->getDecl()->getQualifiedNameAsString());
             cp.set_id(common::to_id(*record_type->getDecl()));
         }
         else if (const auto *tsp =
@@ -1488,7 +1492,8 @@ bool translation_unit_visitor::find_relationships(const clang::QualType &type,
                         ->getID(),
                     relationship_hint);
             }
-            for (const auto &template_argument : *type_instantiation_decl) {
+            for (const auto &template_argument :
+                type_instantiation_decl->template_arguments()) {
                 const auto template_argument_kind = template_argument.getKind();
                 if (template_argument_kind ==
                     clang::TemplateArgument::ArgKind::Integral) {
@@ -2520,12 +2525,31 @@ void translation_unit_visitor::
     argument.set_type(
         common::to_string(arg.getAsType(), template_decl->getASTContext()));
 
-    if (const auto *record_type = arg.getAsType()->getAs<clang::RecordType>();
-        record_type != nullptr) {
+    if (const auto *tsp =
+            arg.getAsType()->getAs<clang::TemplateSpecializationType>();
+        tsp != nullptr) {
+        if (const auto *record_type_decl = tsp->getAsRecordDecl();
+            record_type_decl != nullptr) {
+
+            argument.set_id(common::to_id(arg));
+            if (diagram().should_include(full_template_specialization_name)) {
+                // Add dependency relationship to the parent
+                // template
+                template_instantiation.add_relationship(
+                    {relationship_t::kDependency, common::to_id(arg)});
+            }
+        }
+    }
+    else if (const auto *record_type =
+                 arg.getAsType()->getAs<clang::RecordType>();
+             record_type != nullptr) {
         if (const auto *record_type_decl = record_type->getAsRecordDecl();
             record_type_decl != nullptr) {
-            argument.set_id(common::to_id(arg));
 
+            argument.set_id(common::to_id(arg));
+#if LLVM_VERSION_MAJOR >= 16
+            argument.set_type(record_type_decl->getQualifiedNameAsString());
+#endif
             if (diagram().should_include(full_template_specialization_name)) {
                 // Add dependency relationship to the parent
                 // template
@@ -2635,11 +2659,10 @@ void translation_unit_visitor::process_field(
     if (type_name.find("std::weak_ptr") == 0)
         relationship_hint = relationship_t::kAssociation;
 
-    const auto *template_field_type =
-        field_type->getAs<clang::TemplateSpecializationType>();
-
     found_relationships_t relationships;
 
+    const auto *template_field_type =
+        field_type->getAs<clang::TemplateSpecializationType>();
     // TODO: Refactor to an unalias_type() method
     if (template_field_type != nullptr)
         if (template_field_type->isTypeAlias())
@@ -2803,11 +2826,14 @@ void translation_unit_visitor::finalize()
 bool translation_unit_visitor::simplify_system_template(
     template_parameter &ct, const std::string &full_name) const
 {
-    if (config().type_aliases().count(full_name) > 0) {
-        ct.set_type(config().type_aliases().at(full_name));
+    auto simplified = config().simplify_template_type(full_name);
+
+    if (simplified != full_name) {
+        ct.set_type(simplified);
         ct.clear_params();
         return true;
     }
+
     return false;
 }
 
diff --git a/src/cli/cli_handler.cc b/src/cli/cli_handler.cc
index 7bad2977..44385153 100644
--- a/src/cli/cli_handler.cc
+++ b/src/cli/cli_handler.cc
@@ -268,13 +268,10 @@ cli_flow_t cli_handler::handle_post_config_options()
 
 cli_flow_t cli_handler::print_version()
 {
-    constexpr auto kLLVMBackendPackageStringLength{5};
     ostr_ << "clang-uml " << clanguml::version::CLANG_UML_VERSION << '\n';
     ostr_ << "Copyright (C) 2021-2023 Bartek Kryza <bkryza@gmail.com>" << '\n';
     ostr_ << "Built against LLVM/Clang libraries version: "
-          << std::string{BACKEND_PACKAGE_STRING}.substr(
-                 kLLVMBackendPackageStringLength)
-          << std::endl;
+          << LLVM_VERSION_STRING << std::endl;
     ostr_ << "Using LLVM/Clang libraries version: "
           << clang::getClangFullVersion() << std::endl;
 
diff --git a/src/common/clang_utils.cc b/src/common/clang_utils.cc
index f9c42fcf..07eb980b 100644
--- a/src/common/clang_utils.cc
+++ b/src/common/clang_utils.cc
@@ -115,9 +115,13 @@ std::string get_tag_name(const clang::TagDecl &declaration)
 std::string to_string(const clang::QualType &type, const clang::ASTContext &ctx,
     bool try_canonical)
 {
-    const clang::PrintingPolicy print_policy(ctx.getLangOpts());
+    clang::PrintingPolicy print_policy(ctx.getLangOpts());
+    print_policy.SuppressScope = false;
+    print_policy.PrintCanonicalTypes = false;
 
-    auto result{type.getAsString(print_policy)};
+    std::string result;
+
+    result = type.getAsString(print_policy);
 
     if (try_canonical && result.find('<') != std::string::npos) {
         auto canonical_type_name =
diff --git a/src/config/config.cc b/src/config/config.cc
index 7e2190ca..d00a3333 100644
--- a/src/config/config.cc
+++ b/src/config/config.cc
@@ -121,7 +121,8 @@ void inheritable_diagram_options::inherit(
 std::string inheritable_diagram_options::simplify_template_type(
     std::string full_name) const
 {
-    const auto &aliases = type_aliases();
+    type_aliases_longer_first_t aliases;
+    aliases.insert(type_aliases().begin(), type_aliases().end());
 
     for (const auto &[pattern, replacement] : aliases) {
         util::replace_all(full_name, pattern, replacement);
@@ -204,6 +205,11 @@ void diagram::initialize_type_aliases()
         type_aliases().insert(
             {"std::integral_constant<bool,false>", "std::false_type"});
     }
+#if LLVM_VERSION_MAJOR >= 16
+    if (type_aliases().count("std::basic_string") == 0U) {
+        type_aliases().insert({"std::basic_string", "std::string"});
+    }
+#endif
 }
 
 common::model::diagram_t class_diagram::type() const
diff --git a/src/config/config.h b/src/config/config.h
index 1a5c1172..20f2cc09 100644
--- a/src/config/config.h
+++ b/src/config/config.h
@@ -133,6 +133,8 @@ struct relationship_hint_t {
 using relationship_hints_t = std::map<std::string, relationship_hint_t>;
 
 using type_aliases_t = std::map<std::string, std::string>;
+using type_aliases_longer_first_t =
+    std::map<std::string, std::string, std::greater<>>;
 
 enum class location_t { marker, fileline, function };
 
diff --git a/src/include_diagram/visitor/translation_unit_visitor.cc b/src/include_diagram/visitor/translation_unit_visitor.cc
index 6f47e1ea..40d411d6 100644
--- a/src/include_diagram/visitor/translation_unit_visitor.cc
+++ b/src/include_diagram/visitor/translation_unit_visitor.cc
@@ -43,7 +43,15 @@ translation_unit_visitor::include_visitor::include_visitor(
 {
 }
 
-#if LLVM_VERSION_MAJOR > 14
+#if LLVM_VERSION_MAJOR >= 16
+void translation_unit_visitor::include_visitor::InclusionDirective(
+    clang::SourceLocation hash_loc, const clang::Token & /*include_tok*/,
+    clang::StringRef /*file_name*/, bool is_angled,
+    clang::CharSourceRange /*filename_range*/, clang::OptionalFileEntryRef file,
+    clang::StringRef /*search_path*/, clang::StringRef relative_path,
+    const clang::Module * /*imported*/,
+    clang::SrcMgr::CharacteristicKind file_type)
+#elif LLVM_VERSION_MAJOR > 14
 void translation_unit_visitor::include_visitor::InclusionDirective(
     clang::SourceLocation hash_loc, const clang::Token & /*include_tok*/,
     clang::StringRef /*file_name*/, bool is_angled,
diff --git a/src/include_diagram/visitor/translation_unit_visitor.h b/src/include_diagram/visitor/translation_unit_visitor.h
index 942db8f8..acc895af 100644
--- a/src/include_diagram/visitor/translation_unit_visitor.h
+++ b/src/include_diagram/visitor/translation_unit_visitor.h
@@ -49,7 +49,14 @@ public:
 
         ~include_visitor() override = default;
 
-#if LLVM_VERSION_MAJOR > 14
+#if LLVM_VERSION_MAJOR >= 16
+        void InclusionDirective(clang::SourceLocation HashLoc,
+            const clang::Token &IncludeTok, clang::StringRef FileName,
+            bool IsAngled, clang::CharSourceRange FilenameRange,
+            clang::OptionalFileEntryRef File, clang::StringRef SearchPath,
+            clang::StringRef RelativePath, const clang::Module *Imported,
+            clang::SrcMgr::CharacteristicKind FileType) override;
+#elif LLVM_VERSION_MAJOR > 14
         void InclusionDirective(clang::SourceLocation hash_loc,
             const clang::Token &include_tok, clang::StringRef file_name,
             bool is_angled, clang::CharSourceRange filename_range,
diff --git a/src/package_diagram/visitor/translation_unit_visitor.cc b/src/package_diagram/visitor/translation_unit_visitor.cc
index d12f4a3f..01deefba 100644
--- a/src/package_diagram/visitor/translation_unit_visitor.cc
+++ b/src/package_diagram/visitor/translation_unit_visitor.cc
@@ -344,7 +344,7 @@ bool translation_unit_visitor::find_relationships(const clang::QualType &type,
                  type->getAs<clang::TemplateSpecializationType>()) {
         if (template_specialization_type != nullptr) {
             for (const auto &template_argument :
-                *template_specialization_type) {
+                template_specialization_type->template_arguments()) {
                 const auto template_argument_kind = template_argument.getKind();
                 if (template_argument_kind ==
                     clang::TemplateArgument::ArgKind::Integral) {
diff --git a/src/sequence_diagram/visitor/translation_unit_visitor.cc b/src/sequence_diagram/visitor/translation_unit_visitor.cc
index c9f9e3ee..c2b9f11a 100644
--- a/src/sequence_diagram/visitor/translation_unit_visitor.cc
+++ b/src/sequence_diagram/visitor/translation_unit_visitor.cc
@@ -2064,12 +2064,7 @@ bool translation_unit_visitor::simplify_system_template(
 std::string translation_unit_visitor::simplify_system_template(
     const std::string &full_name) const
 {
-    std::string result{full_name};
-    for (const auto &[k, v] : config().type_aliases()) {
-        util::replace_all(result, k, v);
-    }
-
-    return result;
+    return config().simplify_template_type(full_name);
 }
 
 std::string translation_unit_visitor::make_lambda_name(
diff --git a/tests/t00008/test_case.h b/tests/t00008/test_case.h
index 8687106e..f3288622 100644
--- a/tests/t00008/test_case.h
+++ b/tests/t00008/test_case.h
@@ -64,8 +64,12 @@ TEST_CASE("t00008", "[test-case][class]")
 
         using namespace json;
 
+#if LLVM_VERSION_MAJOR >= 16
+        REQUIRE(IsClassTemplate(j, "A<T,P=T,CMP=nullptr,int N=3>"));
+#else
         REQUIRE(IsClassTemplate(
             j, "A<T,P=T,clanguml::t00008::CMP=nullptr,int N=3>"));
+#endif
         REQUIRE(IsClassTemplate(j, "E::nested_template<ET>"));
         REQUIRE(IsClass(j, "E::nested_template<char>"));
 
diff --git a/tests/t00014/test_case.h b/tests/t00014/test_case.h
index f336750d..d1868352 100644
--- a/tests/t00014/test_case.h
+++ b/tests/t00014/test_case.h
@@ -70,8 +70,13 @@ TEST_CASE("t00014", "[test-case][class]")
 
         REQUIRE_THAT(
             puml, IsField<Public>("cb", "SimpleCallback<ACharString>"));
+#if LLVM_VERSION_MAJOR >= 16
+        REQUIRE_THAT(
+            puml, IsField<Public>("gcb", "GenericCallback<AWCharString>"));
+#else
         REQUIRE_THAT(
             puml, IsField<Public>("gcb", "GenericCallback<R::AWCharString>"));
+#endif
         REQUIRE_THAT(puml, IsField<Public>("vcb", "VoidCallback"));
 
         REQUIRE_THAT(puml,
diff --git a/tests/test_cases.h b/tests/test_cases.h
index 944911b0..4b70a55f 100644
--- a/tests/test_cases.h
+++ b/tests/test_cases.h
@@ -620,6 +620,26 @@ struct File {
     const std::string file;
 };
 
+std::optional<nlohmann::json> get_element_by_id(
+    const nlohmann::json &j, const std::string &id)
+{
+    if (!j.contains("elements"))
+        return {};
+
+    for (const nlohmann::json &e : j["elements"]) {
+        if (e["id"] == id)
+            return {e};
+
+        if (e["type"] == "namespace" || e["type"] == "folder") {
+            auto maybe_e = get_element_by_id(e, id);
+            if (maybe_e)
+                return maybe_e;
+        }
+    }
+
+    return {};
+}
+
 std::optional<nlohmann::json> get_element(
     const nlohmann::json &j, const std::string &name)
 {
@@ -744,15 +764,16 @@ bool IsDeprecated(const nlohmann::json &j, const std::string &name)
 bool IsBaseClass(const nlohmann::json &j, const std::string &base,
     const std::string &subclass)
 {
-    auto sc = get_element(j, expand_name(j, subclass));
+    auto base_el = get_element(j, expand_name(j, base));
+    auto subclass_el = get_element(j, expand_name(j, subclass));
 
-    if (!sc)
+    if (!base_el || !subclass_el)
         return false;
 
-    const nlohmann::json &bases = (*sc)["bases"];
+    const nlohmann::json &bases = (*subclass_el)["bases"];
 
     return std::find_if(bases.begin(), bases.end(), [&](const auto &it) {
-        return it["name"] == expand_name(j, base);
+        return it["id"] == base_el.value()["id"];
     }) != bases.end();
 }