diff --git a/src/common/model/diagram_element.cc b/src/common/model/diagram_element.cc
index 4051b7c7..987505bd 100644
--- a/src/common/model/diagram_element.cc
+++ b/src/common/model/diagram_element.cc
@@ -42,7 +42,8 @@ void diagram_element::set_parent_element_id(common::id_t id)
 
 std::string diagram_element::alias() const
 {
-    assert(id_.value() >= 0);
+    // Only generate alias for global id's
+    assert(id_.is_global());
 
     return fmt::format("C_{:022}", id_.value());
 }
diff --git a/src/sequence_diagram/generators/json/sequence_diagram_generator.cc b/src/sequence_diagram/generators/json/sequence_diagram_generator.cc
index d401cf35..a4e01c88 100644
--- a/src/sequence_diagram/generators/json/sequence_diagram_generator.cc
+++ b/src/sequence_diagram/generators/json/sequence_diagram_generator.cc
@@ -744,11 +744,11 @@ void generator::generate_diagram(nlohmann::json &parent) const
     for (const auto &to_location : config().to()) {
         auto to_activity_id = model().get_to_activity_id(to_location);
 
-        if (to_activity_id == 0)
+        if (!to_activity_id.has_value())
             continue;
 
         auto message_chains_unique = model().get_all_from_to_message_chains(
-            common::id_t{}, *to_activity_id);
+            common::id_t{}, to_activity_id.value());
 
         nlohmann::json sequence;
         sequence["to"]["location"] = to_location.location;
diff --git a/src/sequence_diagram/model/participant.cc b/src/sequence_diagram/model/participant.cc
index 8c5dbc22..28969acf 100644
--- a/src/sequence_diagram/model/participant.cc
+++ b/src/sequence_diagram/model/participant.cc
@@ -178,7 +178,7 @@ std::string method::method_name() const { return method_name_; }
 
 std::string method::alias() const
 {
-    assert(class_id_.value() >= 0);
+    assert(class_id_.is_global());
 
     return fmt::format("C_{:022}", class_id_.value());
 }
diff --git a/src/sequence_diagram/visitor/call_expression_context.cc b/src/sequence_diagram/visitor/call_expression_context.cc
index 241c9bd7..50dedcdb 100644
--- a/src/sequence_diagram/visitor/call_expression_context.cc
+++ b/src/sequence_diagram/visitor/call_expression_context.cc
@@ -133,7 +133,7 @@ void call_expression_context::update(
 common::id_t call_expression_context::caller_id() const
 {
     if (lambda_caller_id().has_value())
-        return *lambda_caller_id();
+        return *lambda_caller_id(); // NOLINT
 
     return current_caller_id_;
 }
diff --git a/src/sequence_diagram/visitor/translation_unit_visitor.cc b/src/sequence_diagram/visitor/translation_unit_visitor.cc
index b8fe4c8a..bffe738e 100644
--- a/src/sequence_diagram/visitor/translation_unit_visitor.cc
+++ b/src/sequence_diagram/visitor/translation_unit_visitor.cc
@@ -1934,11 +1934,11 @@ std::string translation_unit_visitor::make_lambda_name(
         // Parent is also a lambda (this id points to a lambda operator())
         std::string parent_lambda_class_name{"()"};
         if (diagram().get_participant<model::method>(
-                context().lambda_caller_id().value())) {
+                context().lambda_caller_id().value())) { // NOLINT
             auto parent_lambda_class_id =
                 diagram()
                     .get_participant<model::method>(
-                        context().lambda_caller_id().value())
+                        context().lambda_caller_id().value()) // NOLINT
                     .value()
                     .class_id();