diff --git a/src/class_diagram/generators/json/class_diagram_generator.cc b/src/class_diagram/generators/json/class_diagram_generator.cc
index bcccc383..451ec035 100644
--- a/src/class_diagram/generators/json/class_diagram_generator.cc
+++ b/src/class_diagram/generators/json/class_diagram_generator.cc
@@ -45,21 +45,13 @@ void to_json(nlohmann::json &j, const element &c)
 void to_json(nlohmann::json &j, const template_parameter &c)
 {
     j["kind"] = to_string(c.kind());
-
-    if (c.kind() == template_parameter_kind_t::template_type) {
+    if (c.type())
+        j["type"] = c.type().value();
+    if (c.name())
         j["name"] = c.name().value();
-    }
-
-    //    j["type"] = c.type();
-    //    j["name"] = c.name();
-    //    if (!c.default_value().empty())
-    //        j["default_value"] = c.default_value();
-    //    j["is_template_parameter"] = c.is_template_parameter();
-    //    j["is_template_template_parameter"] =
-    //    c.is_template_template_parameter(); if (const auto &constraint =
-    //    c.concept_constraint(); constraint)
-    //        j["concept_constraint"] = constraint.value();
-    //    j["is_variadic"] = c.is_variadic();
+    if (c.default_value())
+        j["default"] = c.default_value().value();
+    j["is_variadic"] = c.is_variadic();
 }
 
 void to_json(nlohmann::json &j, const relationship &c)
diff --git a/src/common/model/template_parameter.cc b/src/common/model/template_parameter.cc
index f7c4aca5..662f6286 100644
--- a/src/common/model/template_parameter.cc
+++ b/src/common/model/template_parameter.cc
@@ -40,16 +40,6 @@ std::string to_string(template_parameter_kind_t k)
         assert(0);
     }
 }
-// template_parameter::template_parameter(const std::optional<std::string>
-// &type,
-//     const std::optional<std::string> &name,
-//     const std::optional<std::string> &default_value, bool is_variadic)
-//     : type_{type}
-//     , name_{name}
-//     , default_value_{std::move(default_value)}
-//     , is_variadic_{is_variadic}
-//{
-// }
 
 void template_parameter::set_type(const std::string &type)
 {
diff --git a/src/common/model/template_parameter.h b/src/common/model/template_parameter.h
index 7ebba8de..4a8453c2 100644
--- a/src/common/model/template_parameter.h
+++ b/src/common/model/template_parameter.h
@@ -43,8 +43,6 @@ std::string to_string(template_parameter_kind_t k);
 /// including variadic parameters and instantiations with
 /// nested templates
 class template_parameter {
-    template_parameter() = default;
-
 public:
     static template_parameter make_template_type(std::string name,
         const std::optional<std::string> &default_value = {},
@@ -107,13 +105,6 @@ public:
         return p;
     }
 
-    //    template_parameter(const std::optional<std::string> &type = {},
-    //        const std::optional<std::string> &name = {},
-    //        const std::optional<std::string> &default_value = {},
-    //        bool is_variadic = false);
-
-    //    template_parameter(const template_parameter &right) = default;
-
     void set_type(const std::string &type);
     std::optional<std::string> type() const;
 
@@ -129,9 +120,6 @@ public:
     void is_variadic(bool is_variadic) noexcept;
     bool is_variadic() const noexcept;
 
-    void is_pack(bool is_pack) noexcept;
-    bool is_pack() const noexcept;
-
     bool is_specialization_of(const template_parameter &ct) const;
 
     friend bool operator==(
@@ -188,6 +176,8 @@ public:
     void set_unexposed(bool unexposed) { is_unexposed_ = unexposed; }
 
 private:
+    template_parameter() = default;
+
     template_parameter_kind_t kind_;
 
     /// Represents the type of non-type template parameters
@@ -211,9 +201,6 @@ private:
     /// Whether the template parameter is variadic
     bool is_variadic_{false};
 
-    /// Whether the argument specializes argument pack from parent template
-    bool is_pack_{false};
-
     /// Stores optional fully qualified name of constraint for this template
     /// parameter
     std::optional<std::string> concept_constraint_;
diff --git a/src/sequence_diagram/visitor/translation_unit_visitor.cc b/src/sequence_diagram/visitor/translation_unit_visitor.cc
index 27a7fb8f..b93c1e73 100644
--- a/src/sequence_diagram/visitor/translation_unit_visitor.cc
+++ b/src/sequence_diagram/visitor/translation_unit_visitor.cc
@@ -1588,7 +1588,6 @@ void translation_unit_visitor::
     assert(arg.getKind() == clang::TemplateArgument::Type);
 
     argument.is_template_parameter(false);
-
     argument.set_type(
         common::to_string(arg.getAsType(), template_decl->getASTContext()));
 }
@@ -1603,9 +1602,7 @@ translation_unit_visitor::build_template_instantiation_process_type_argument(
 {
     assert(arg.getKind() == clang::TemplateArgument::Type);
 
-    auto argument = template_parameter::make_argument({});
-
-    argument.is_template_parameter(false);
+    std::optional<template_parameter> argument;
 
     // If this is a nested template type - add nested templates as
     // template arguments
@@ -1621,27 +1618,27 @@ translation_unit_visitor::build_template_instantiation_process_type_argument(
                 .getAsTemplateDecl()
                 ->getQualifiedNameAsString();
 
-        argument.set_type(nested_template_name);
+        argument = template_parameter::make_argument(nested_template_name);
 
         // Check if this template should be simplified (e.g. system
         // template aliases such as 'std:basic_string<char>' should
         // be simply 'std::string')
-        simplify_system_template(
-            argument, argument.to_string(config().using_namespace(), false));
+        simplify_system_template(*argument,
+            argument.value().to_string(config().using_namespace(), false));
     }
     else if (arg.getAsType()->getAs<clang::TemplateTypeParmType>() != nullptr) {
-        argument.is_template_parameter(true);
-        argument.set_type(
+        argument = template_parameter::make_template_type(
             common::to_string(arg.getAsType(), template_decl->getASTContext()));
     }
     else {
+        argument = template_parameter::make_argument({});
         // This is just a regular record type
         build_template_instantiation_process_tag_argument(
             template_instantiation, full_template_specialization_name,
-            template_decl, arg, argument);
+            template_decl, arg, *argument);
     }
 
-    return argument;
+    return *argument;
 }
 
 std::unique_ptr<model::class_>