diff --git a/src/class_diagram/visitor/translation_unit_visitor.cc b/src/class_diagram/visitor/translation_unit_visitor.cc
index fbc0ffc7..c02d8868 100644
--- a/src/class_diagram/visitor/translation_unit_visitor.cc
+++ b/src/class_diagram/visitor/translation_unit_visitor.cc
@@ -255,7 +255,7 @@ bool translation_unit_visitor::VisitTypeAliasTemplateDecl(
         cls->getQualifiedNameAsString(),
         cls->getLocation().printToString(source_manager()));
 
-    auto *template_type_specialization_ptr =
+    const auto *template_type_specialization_ptr =
         cls->getTemplatedDecl()
             ->getUnderlyingType()
             ->getAs<clang::TemplateSpecializationType>();
@@ -618,7 +618,7 @@ void translation_unit_visitor::process_record_containment(
 void translation_unit_visitor::process_class_bases(
     const clang::CXXRecordDecl *cls, class_ &c)
 {
-    for (auto &base : cls->bases()) {
+    for (const auto &base : cls->bases()) {
         class_parent cp;
         auto name_and_ns = common::model::namespace_{
             common::to_string(base.getType(), cls->getASTContext())};
@@ -1481,14 +1481,14 @@ std::unique_ptr<class_> translation_unit_visitor::build_template_instantiation(
         /*is variadic */ bool>>
         template_base_params{};
 
-    auto *template_type_ptr = &template_type_decl;
+    const auto *template_type_ptr = &template_type_decl;
     if (template_type_decl.isTypeAlias() &&
         (template_type_decl.getAliasedType()
                 ->getAs<clang::TemplateSpecializationType>() != nullptr))
         template_type_ptr = template_type_decl.getAliasedType()
                                 ->getAs<clang::TemplateSpecializationType>();
 
-    auto &template_type = *template_type_ptr;
+    const auto &template_type = *template_type_ptr;
 
     //
     // Create class_ instance to hold the template instantiation
@@ -2129,7 +2129,7 @@ void translation_unit_visitor::resolve_local_to_global_ids()
 {
     // TODO: Refactor to a map with relationships attached to references
     //       to elements
-    for (auto &cls : diagram().classes()) {
+    for (const auto &cls : diagram().classes()) {
         for (auto &rel : cls.get().relationships()) {
             if (rel.type() == relationship_t::kInstantiation) {
                 const auto maybe_local_id = rel.destination();
diff --git a/src/sequence_diagram/visitor/translation_unit_visitor.cc b/src/sequence_diagram/visitor/translation_unit_visitor.cc
index 8ebeda90..e09ac3e4 100644
--- a/src/sequence_diagram/visitor/translation_unit_visitor.cc
+++ b/src/sequence_diagram/visitor/translation_unit_visitor.cc
@@ -1000,7 +1000,7 @@ bool translation_unit_visitor::process_class_method_call_expression(
 
     std::string method_name = method_decl->getQualifiedNameAsString();
 
-    auto *callee_decl =
+    const auto *callee_decl =
         method_decl != nullptr ? method_decl->getParent() : nullptr;
 
     if (callee_decl == nullptr)
@@ -1026,7 +1026,7 @@ bool translation_unit_visitor::process_class_method_call_expression(
 bool translation_unit_visitor::process_class_template_method_call_expression(
     model::message &m, const clang::CallExpr *expr)
 {
-    auto *dependent_member_callee =
+    const auto *dependent_member_callee =
         clang::dyn_cast_or_null<clang::CXXDependentScopeMemberExpr>(
             expr->getCallee());
 
@@ -1145,7 +1145,7 @@ bool translation_unit_visitor::process_unresolved_lookup_call_expression(
     model::message &m, const clang::CallExpr *expr)
 {
     // This is probably a template
-    auto *unresolved_expr =
+    const auto *unresolved_expr =
         clang::dyn_cast_or_null<clang::UnresolvedLookupExpr>(expr->getCallee());
 
     if (unresolved_expr != nullptr) {
@@ -1153,7 +1153,7 @@ bool translation_unit_visitor::process_unresolved_lookup_call_expression(
             if (clang::dyn_cast_or_null<clang::FunctionTemplateDecl>(decl) !=
                 nullptr) {
                 // Yes, it's a template
-                auto *ftd =
+                const auto *ftd =
                     clang::dyn_cast_or_null<clang::FunctionTemplateDecl>(decl);
 
                 if (!get_unique_id(ftd->getID()).has_value())
@@ -1820,14 +1820,14 @@ translation_unit_visitor::build_template_instantiation(
         /*is variadic */ bool>>
         template_base_params{};
 
-    auto *template_type_ptr = &template_type_decl;
+    const auto *template_type_ptr = &template_type_decl;
     if (template_type_decl.isTypeAlias() &&
         (template_type_decl.getAliasedType()
                 ->getAs<clang::TemplateSpecializationType>() != nullptr))
         template_type_ptr = template_type_decl.getAliasedType()
                                 ->getAs<clang::TemplateSpecializationType>();
 
-    auto &template_type = *template_type_ptr;
+    const auto &template_type = *template_type_ptr;
 
     //
     // Create class_ instance to hold the template instantiation