diff --git a/src/sequence_diagram/generators/plantuml/sequence_diagram_generator.cc b/src/sequence_diagram/generators/plantuml/sequence_diagram_generator.cc
index 0d65b040..b3a154fe 100644
--- a/src/sequence_diagram/generators/plantuml/sequence_diagram_generator.cc
+++ b/src/sequence_diagram/generators/plantuml/sequence_diagram_generator.cc
@@ -60,7 +60,7 @@ void generator::generate_call(const message &m, std::ostream &ostr) const
          << to.value().alias() << " : " << message << std::endl;
 
     LOG_DBG("Generated call '{}' from {} [{}] to {} [{}]", message, from,
-        m.from_name, to, m.to_name);
+        m.from, to, m.to);
 }
 
 void generator::generate_return(const message &m, std::ostream &ostr) const
@@ -84,19 +84,19 @@ void generator::generate_activity(const activity &a, std::ostream &ostr) const
         if (!to)
             continue;
 
-        LOG_DBG("Generating message {} --> {}", m.from_name, m.to_name);
+        LOG_DBG("Generating message {} --> {}", m.from, m.to);
         generate_call(m, ostr);
 
         ostr << "activate " << to.value().alias() << std::endl;
 
         if (m_model.sequences.find(m.to) != m_model.sequences.end()) {
             LOG_DBG("Creating activity {} --> {} - missing sequence {}",
-                m.from_name, m.to_name, m.to);
+                m.from, m.to, m.to);
             generate_activity(m_model.sequences[m.to], ostr);
         }
         else
             LOG_DBG("Skipping activity {} --> {} - missing sequence {}",
-                m.from_name, m.to_name, m.to);
+                m.from, m.to, m.to);
 
         generate_return(m, ostr);
 
@@ -159,6 +159,8 @@ void generator::generate(std::ostream &ostr) const
 {
     m_model.print();
 
+
+
     ostr << "@startuml" << std::endl;
 
     generate_plantuml_directives(ostr, m_config.puml().before);
@@ -167,7 +169,8 @@ void generator::generate(std::ostream &ostr) const
         if (sf.location_type == source_location::location_t::function) {
             std::int64_t start_from;
             for (const auto &[k, v] : m_model.sequences) {
-                std::string vfrom = v.from;
+                const auto& caller = *m_model.participants.at(v.from);
+                std::string vfrom = caller.full_name(false);
                 if (vfrom == sf.location) {
                     LOG_DBG("Found sequence diagram start point: {}", k);
                     start_from = k;
diff --git a/src/sequence_diagram/model/activity.h b/src/sequence_diagram/model/activity.h
index d60cb225..bee9c4d7 100644
--- a/src/sequence_diagram/model/activity.h
+++ b/src/sequence_diagram/model/activity.h
@@ -18,6 +18,7 @@
 #pragma once
 
 #include "message.h"
+#include "participant.h"
 
 #include <string>
 #include <vector>
@@ -25,8 +26,10 @@
 namespace clanguml::sequence_diagram::model {
 
 struct activity {
-    std::uint_least64_t usr;
-    std::string from;
+//    std::uint_least64_t from_id;
+//    std::string from_name;
+//    std::string from_method_name;
+    common::model::diagram_element::id_t from;
     std::vector<message> messages;
 };
 
diff --git a/src/sequence_diagram/model/diagram.cc b/src/sequence_diagram/model/diagram.cc
index e919938a..6f6616b6 100644
--- a/src/sequence_diagram/model/diagram.cc
+++ b/src/sequence_diagram/model/diagram.cc
@@ -73,13 +73,25 @@ inja::json diagram::context() const
 
 void diagram::print() const
 {
+    LOG_DBG(" --- Participants ---");
+    for (const auto &[id, participant] : participants) {
+        LOG_DBG("{} - {}", id, participant->to_string());
+    }
+
+    LOG_DBG(" --- Activities ---");
     for (const auto &[from_id, act] : sequences) {
         LOG_DBG("Sequence id={}:", from_id);
-        LOG_DBG("   Activity id={}, from={}:", act.usr, act.from);
+        const auto &from_activity = *(participants.at(from_id));
+        LOG_DBG("   Activity id={}, from={}:", act.from,
+            from_activity.full_name(false));
         for (const auto &message : act.messages) {
-            LOG_DBG(
-                "       Message from={}, from_id={}, to={}, to_id={}, name={}",
-                message.from_name, message.from, message.to_name, message.to,
+            const auto &from_participant = *participants.at(message.from);
+            const auto &to_participant = *participants.at(message.to);
+
+            LOG_DBG("       Message from={}, from_id={}, "
+                    "to={}, to_id={}, name={}",
+                from_participant.full_name(false), from_participant.id(),
+                to_participant.full_name(false), to_participant.id(),
                 message.message_name);
         }
     }
diff --git a/src/sequence_diagram/model/diagram.h b/src/sequence_diagram/model/diagram.h
index 4b66d149..6f12f911 100644
--- a/src/sequence_diagram/model/diagram.h
+++ b/src/sequence_diagram/model/diagram.h
@@ -66,16 +66,16 @@ public:
 
     void add_participant(std::unique_ptr<participant> p)
     {
-        LOG_DBG("Adding {} participant: {}, {} [{}]", p->type_name(),
-            p->full_name(false), p->id(),
-            p->type_name() == "method"
-                ? dynamic_cast<method *>(p.get())->method_name()
-                : "");
+        const auto participant_id = p->id();
 
-        const auto pid = p->id();
+        if (participants.find(participant_id) == participants.end()) {
+            LOG_DBG("Adding '{}' participant: {}, {} [{}]", p->type_name(),
+                p->full_name(false), p->id(),
+                p->type_name() == "method"
+                    ? dynamic_cast<method *>(p.get())->method_name()
+                    : "");
 
-        if (participants.find(pid) == participants.end()) {
-            participants.emplace(pid, std::move(p));
+            participants.emplace(participant_id, std::move(p));
         }
     }
 
diff --git a/src/sequence_diagram/model/message.h b/src/sequence_diagram/model/message.h
index 606fa95a..07087964 100644
--- a/src/sequence_diagram/model/message.h
+++ b/src/sequence_diagram/model/message.h
@@ -18,6 +18,7 @@
 #pragma once
 
 #include "common/model/enums.h"
+#include "participant.h"
 
 #include <string>
 #include <vector>
@@ -27,9 +28,10 @@ namespace clanguml::sequence_diagram::model {
 struct message {
     message()
         : from{}
-        , from_name{}
+//        , from_method_name{}
+//        , from_name{}
         , to{}
-        , to_name{}
+//        , to_name{}
         , message_name{}
         , return_type{}
         , line{}
@@ -37,17 +39,21 @@ struct message {
     }
 
     common::model::message_t type;
-
-    /// Source participant id
-    std::uint_least64_t from;
-    std::string from_name;
-    //    std::uint_least64_t from_usr{};
-
-    /// Target participant id
-    std::uint_least64_t to;
-    std::string to_name;
-
-    //    std::int64_t to_usr{};
+    common::model::diagram_element::id_t from;
+    common::model::diagram_element::id_t to;
+//
+//    /// Source participant id
+//    std::uint_least64_t from;
+//    std::string from_method_name;
+//
+//    std::string from_name;
+//    //    std::uint_least64_t from_usr{};
+//
+//    /// Target participant id
+//    std::uint_least64_t to;
+//    std::string to_name;
+//
+//    //    std::int64_t to_usr{};
 
     std::string message_name;
 
diff --git a/src/sequence_diagram/model/participant.h b/src/sequence_diagram/model/participant.h
index 1990c7ec..e8a77efd 100644
--- a/src/sequence_diagram/model/participant.h
+++ b/src/sequence_diagram/model/participant.h
@@ -66,6 +66,12 @@ struct participant : public common::model::element,
 
     std::string type_name() const override { return "participant"; }
 
+    virtual std::string to_string() const
+    {
+        return fmt::format("Participant '{}': id={} name={}", type_name(), id(),
+            full_name(false));
+    }
+
     stereotype_t stereotype_{stereotype_t::participant};
 };
 
@@ -148,6 +154,12 @@ struct method : public participant {
 
     diagram_element::id_t class_id() const { return class_id_; }
 
+    std::string to_string() const override
+    {
+        return fmt::format("Participant '{}': id={}, name={}, class_id={}",
+            type_name(), id(), full_name(false), class_id());
+    }
+
 private:
     diagram_element::id_t class_id_;
     std::string method_name_;
diff --git a/src/sequence_diagram/visitor/translation_unit_visitor.cc b/src/sequence_diagram/visitor/translation_unit_visitor.cc
index b908a934..7d06bfff 100644
--- a/src/sequence_diagram/visitor/translation_unit_visitor.cc
+++ b/src/sequence_diagram/visitor/translation_unit_visitor.cc
@@ -78,8 +78,6 @@ bool translation_unit_visitor::VisitCXXRecordDecl(clang::CXXRecordDecl *cls)
     if (!diagram().should_include(cls->getQualifiedNameAsString()))
         return true;
 
-    call_expression_context_.reset();
-
     if (!diagram().should_include(cls->getQualifiedNameAsString())) {
         return true;
     }
@@ -102,6 +100,8 @@ bool translation_unit_visitor::VisitCXXRecordDecl(clang::CXXRecordDecl *cls)
     if (!c_ptr)
         return true;
 
+    call_expression_context_.reset();
+
     const auto cls_id = c_ptr->id();
 
     set_ast_local_id(cls->getID(), cls_id);
@@ -152,9 +152,9 @@ bool translation_unit_visitor::VisitClassTemplateDecl(
     if (!diagram().should_include(cls->getQualifiedNameAsString()))
         return true;
 
-    LOG_DBG("= Visiting class template declaration {} at {}",
+    LOG_DBG("= Visiting class template declaration {} at {} [{}]",
         cls->getQualifiedNameAsString(),
-        cls->getLocation().printToString(source_manager()));
+        cls->getLocation().printToString(source_manager()), (void *)cls);
 
     auto c_ptr = create_class_declaration(cls->getTemplatedDecl());
 
@@ -181,8 +181,7 @@ bool translation_unit_visitor::VisitClassTemplateDecl(
     }
 
     if (diagram_.should_include(*c_ptr)) {
-        const auto name = c_ptr->full_name();
-        LOG_DBG("Adding class template {} with id {}", name, id);
+        LOG_DBG("Adding class template {} with id {}", cls_full_name, id);
 
         call_expression_context_.set_caller_id(id);
         call_expression_context_.update(cls);
@@ -195,7 +194,7 @@ bool translation_unit_visitor::VisitClassTemplateDecl(
 
 bool translation_unit_visitor::VisitCXXMethodDecl(clang::CXXMethodDecl *m)
 {
-    if (call_expression_context_.current_class_decl_ == nullptr ||
+    if (call_expression_context_.current_class_decl_ == nullptr &&
         call_expression_context_.current_class_template_decl_ == nullptr)
         return true;
 
@@ -210,11 +209,22 @@ bool translation_unit_visitor::VisitCXXMethodDecl(clang::CXXMethodDecl *m)
     m_ptr->set_name(ns.name());
     ns.pop_back();
     m_ptr->set_namespace(ns);
-    m_ptr->set_id(common::to_id(m->getQualifiedNameAsString()));
 
-    m_ptr->set_class_id(
-        get_ast_local_id(call_expression_context_.current_class_decl_->getID())
-            .value());
+    if (call_expression_context_.current_class_decl_)
+        m_ptr->set_class_id(get_ast_local_id(
+            call_expression_context_.current_class_decl_->getID())
+                                .value());
+    else
+        m_ptr->set_class_id(get_ast_local_id(
+            call_expression_context_.current_class_template_decl_->getID())
+                                .value());
+
+    m_ptr->set_name(
+        diagram().participants.at(m_ptr->class_id())->full_name_no_ns() +
+        "::" + m->getNameAsString());
+
+    m_ptr->set_id(
+        common::to_id(m_ptr->full_name(false) + "::" + m->getNameAsString()));
 
     call_expression_context_.update(m);
 
@@ -327,6 +337,8 @@ bool translation_unit_visitor::VisitCallExpr(clang::CallExpr *expr)
     using clanguml::sequence_diagram::model::activity;
     using clanguml::sequence_diagram::model::message;
 
+    //    expr->dump();
+
     // Skip casts, moves and such
     if (expr->isCallToStdMove())
         return true;
@@ -337,24 +349,28 @@ bool translation_unit_visitor::VisitCallExpr(clang::CallExpr *expr)
     if (clang::dyn_cast_or_null<clang::ImplicitCastExpr>(expr))
         return true;
 
+    call_expression_context_.dump();
+
     if (!call_expression_context_.valid())
         return true;
 
     message m;
     m.type = message_t::kCall;
     m.from = call_expression_context_.caller_id();
-    m.from_name = diagram().participants.at(m.from)->full_name(false);
 
     const auto &current_ast_context =
         *call_expression_context_.get_ast_context();
 
+    LOG_DBG("Visiting call expression at {}",
+        expr->getBeginLoc().printToString(source_manager()));
+
     if (const auto *operator_call_expr =
             clang::dyn_cast_or_null<clang::CXXOperatorCallExpr>(expr);
         operator_call_expr != nullptr) {
         // TODO: Handle C++ operator calls
     }
     //
-    // class method
+    // Call to a class method
     //
     else if (const auto *method_call_expr =
                  clang::dyn_cast_or_null<clang::CXXMemberCallExpr>(expr);
@@ -376,7 +392,6 @@ bool translation_unit_visitor::VisitCallExpr(clang::CallExpr *expr)
         //       encountered by the visitor - for now it's not a problem
         //       as overloaded methods are not supported
         m.to = common::to_id(method_decl->getQualifiedNameAsString());
-        m.to_name = callee_decl->getQualifiedNameAsString();
         m.message_name = method_decl->getNameAsString();
         m.return_type = method_call_expr->getCallReturnType(current_ast_context)
                             .getAsString();
@@ -385,6 +400,9 @@ bool translation_unit_visitor::VisitCallExpr(clang::CallExpr *expr)
             diagram().add_active_participant(
                 get_ast_local_id(callee_decl->getID()).value());
     }
+    //
+    // Call to a function
+    //
     else if (const auto *function_call_expr =
                  clang::dyn_cast_or_null<clang::CallExpr>(expr);
              function_call_expr != nullptr) {
@@ -396,8 +414,49 @@ bool translation_unit_visitor::VisitCallExpr(clang::CallExpr *expr)
         }
 
         if (!callee_decl) {
-            if (clang::dyn_cast_or_null<clang::UnresolvedLookupExpr>(
+            //
+            // Call to a method of a class template
+            //
+            if (clang::dyn_cast_or_null<clang::CXXDependentScopeMemberExpr>(
                     function_call_expr->getCallee())) {
+                auto *dependent_member_callee =
+                    clang::dyn_cast_or_null<clang::CXXDependentScopeMemberExpr>(
+                        function_call_expr->getCallee());
+
+                if (!dependent_member_callee->getBaseType().isNull()) {
+                    const auto *primary_template =
+                        dependent_member_callee->getBaseType()
+                            ->getAs<clang::TemplateSpecializationType>()
+                            ->getTemplateName()
+                            .getAsTemplateDecl();
+
+                    auto callee_method_full_name =
+                        diagram()
+                            .participants
+                            .at(get_ast_local_id(primary_template->getID())
+                                    .value())
+                            ->full_name(false) +
+                        "::" +
+                        dependent_member_callee->getMember().getAsString();
+
+                    auto callee_id = common::to_id(callee_method_full_name);
+                    m.to = callee_id;
+
+                    m.message_name =
+                        dependent_member_callee->getMember().getAsString();
+                    m.return_type = "";
+
+                    if (get_ast_local_id(primary_template->getID()))
+                        diagram().add_active_participant(
+                            get_ast_local_id(primary_template->getID())
+                                .value());
+                }
+            }
+            //
+            // Call to a template function
+            //
+            else if (clang::dyn_cast_or_null<clang::UnresolvedLookupExpr>(
+                         function_call_expr->getCallee())) {
                 // This is probably a template
                 auto *unresolved_expr =
                     clang::dyn_cast_or_null<clang::UnresolvedLookupExpr>(
@@ -411,7 +470,8 @@ bool translation_unit_visitor::VisitCallExpr(clang::CallExpr *expr)
                             auto *ftd = clang::dyn_cast_or_null<
                                 clang::FunctionTemplateDecl>(decl);
 
-                            m.to_name = to_string(ftd);
+                            //                            m.to_name =
+                            //                            to_string(ftd);
                             m.to = get_ast_local_id(ftd->getID()).value();
                             auto message_name =
                                 diagram()
@@ -430,11 +490,8 @@ bool translation_unit_visitor::VisitCallExpr(clang::CallExpr *expr)
             }
         }
         else {
-            if (!callee_decl)
-                return true;
-
             if (callee_decl->isTemplateDecl())
-                LOG_DBG("Call to template function!!!!");
+                LOG_DBG("Call to template function");
 
             const auto *callee_function = callee_decl->getAsFunction();
 
@@ -473,7 +530,8 @@ bool translation_unit_visitor::VisitCallExpr(clang::CallExpr *expr)
                 LOG_DBG("Processing implicit template specialization {}",
                     f_ptr->full_name(false));
 
-            m.to_name = callee_function->getQualifiedNameAsString();
+            //            m.to_name =
+            //            callee_function->getQualifiedNameAsString();
             if (is_implicit) {
                 // If this is an implicit template specialization/instantiation
                 // for now we just redirect the call to it's primary template
@@ -512,8 +570,8 @@ bool translation_unit_visitor::VisitCallExpr(clang::CallExpr *expr)
     if (m.from > 0 && m.to > 0) {
         if (diagram().sequences.find(m.from) == diagram().sequences.end()) {
             activity a;
-            a.usr = m.from;
-            a.from = m.from_name;
+            //            a.usr = m.from;
+            a.from = m.from;
             diagram().sequences.insert({m.from, std::move(a)});
         }
 
@@ -521,7 +579,7 @@ bool translation_unit_visitor::VisitCallExpr(clang::CallExpr *expr)
         diagram().add_active_participant(m.to);
 
         LOG_DBG("Found call {} from {} [{}] to {} [{}] ", m.message_name,
-            m.from_name, m.from, m.to_name, m.to);
+            m.from, m.from, m.to, m.to);
 
         diagram().sequences[m.from].messages.emplace_back(std::move(m));
 
diff --git a/src/sequence_diagram/visitor/translation_unit_visitor.h b/src/sequence_diagram/visitor/translation_unit_visitor.h
index 3d3e4d31..afb408dc 100644
--- a/src/sequence_diagram/visitor/translation_unit_visitor.h
+++ b/src/sequence_diagram/visitor/translation_unit_visitor.h
@@ -32,6 +32,7 @@ std::string to_string(const clang::FunctionTemplateDecl *decl);
 struct call_expression_context {
     call_expression_context()
         : current_class_decl_{nullptr}
+        , current_class_template_decl_{nullptr}
         , current_method_decl_{nullptr}
         , current_function_decl_{nullptr}
         , current_function_template_decl_{nullptr}
@@ -40,29 +41,40 @@ struct call_expression_context {
 
     void reset()
     {
+        current_caller_id_ = 0;
         current_class_decl_ = nullptr;
+        current_class_template_decl_ = nullptr;
         current_method_decl_ = nullptr;
         current_function_decl_ = nullptr;
         current_function_template_decl_ = nullptr;
     }
 
+    void dump()
+    {
+        LOG_DBG("current_caller_id_ = {}", current_caller_id_);
+        LOG_DBG("current_class_decl_ = {}", (void *)current_class_decl_);
+        LOG_DBG("current_class_template_decl_ = {}",
+            (void *)current_class_template_decl_);
+        LOG_DBG("current_method_decl_ = {}", (void *)current_method_decl_);
+        LOG_DBG("current_function_decl_ = {}", (void *)current_function_decl_);
+        LOG_DBG("current_function_template_decl_ = {}",
+            (void *)current_function_template_decl_);
+    }
+
     bool valid() const
     {
         return (current_class_decl_ != nullptr) ||
+            (current_class_template_decl_ != nullptr) ||
             (current_method_decl_ != nullptr) ||
             (current_function_decl_ != nullptr) ||
             (current_function_template_decl_ != nullptr);
     }
 
-    void update(clang::CXXRecordDecl *cls) { current_class_decl_ = cls; }
-
-    void update(clang::ClassTemplateDecl *clst)
-    {
-        current_class_template_decl_ = clst;
-    }
-
     clang::ASTContext *get_ast_context()
     {
+        if (current_class_template_decl_)
+            return &current_class_template_decl_->getASTContext();
+
         if (current_class_decl_)
             return &current_class_decl_->getASTContext();
 
@@ -72,6 +84,13 @@ struct call_expression_context {
         return &current_function_decl_->getASTContext();
     }
 
+    void update(clang::CXXRecordDecl *cls) { current_class_decl_ = cls; }
+
+    void update(clang::ClassTemplateDecl *clst)
+    {
+        current_class_template_decl_ = clst;
+    }
+
     void update(clang::CXXMethodDecl *method) { current_method_decl_ = method; }
 
     void update(clang::FunctionDecl *function)
@@ -118,73 +137,6 @@ struct call_expression_context {
             current_function_template_decl_ != nullptr;
     }
 
-    //    std::string caller_name() const
-    //    {
-    //        if (in_class_method())
-    //            return current_class_decl_->getQualifiedNameAsString();
-    //        else if (in_function_template()) {
-    //            return to_string(current_function_template_decl_);
-    //        }
-    //        else if (in_function()) {
-    //            const auto function_name =
-    //                current_function_decl_->getQualifiedNameAsString();
-    //            LOG_DBG("Processing function {}", function_name);
-    //            // Handle call expression within free function
-    //            if
-    //            (current_function_decl_->isFunctionTemplateSpecialization()) {
-    //                /*
-    //                    /// This template specialization was formed from a
-    //                   template-id but
-    //                    /// has not yet been declared, defined, or
-    //                    instantiated. TSK_Undeclared = 0,
-    //                    /// This template specialization was implicitly
-    //                    instantiated
-    //                   from a
-    //                    /// template. (C++ [temp.inst]).
-    //                    TSK_ImplicitInstantiation,
-    //                    /// This template specialization was declared or
-    //                    defined by
-    //                   an
-    //                    /// explicit specialization (C++ [temp.expl.spec]) or
-    //                   partial
-    //                    /// specialization (C++ [temp.class.spec]).
-    //                    TSK_ExplicitSpecialization,
-    //                    /// This template specialization was instantiated from
-    //                    a
-    //                   template
-    //                    /// due to an explicit instantiation declaration
-    //                    request
-    //                    /// (C++11 [temp.explicit]).
-    //                    TSK_ExplicitInstantiationDeclaration,
-    //                    /// This template specialization was instantiated from
-    //                    a
-    //                   template
-    //                    /// due to an explicit instantiation definition
-    //                    request
-    //                    /// (C++ [temp.explicit]).
-    //                    TSK_ExplicitInstantiationDefinition
-    //                 */
-    //                [[maybe_unused]] const auto specialization_kind =
-    //                    current_function_decl_->getTemplateSpecializationKind();
-    //                [[maybe_unused]] const auto *primary_template =
-    //                    current_function_decl_->getPrimaryTemplate();
-    //
-    //                for (const auto &arg :
-    //                    current_function_decl_->getTemplateSpecializationArgs()
-    //                        ->asArray()) {
-    //                    LOG_DBG("TEMPLATE SPECIALIZATION ARG:");
-    //                    arg.dump();
-    //                }
-    //
-    //                LOG_DBG("--------------");
-    //            }
-    //
-    //            return function_name + "()";
-    //        }
-    //        else
-    //            return "";
-    //    }
-
     std::int64_t caller_id() const { return current_caller_id_; }
 
     void set_caller_id(std::int64_t id)
diff --git a/tests/t20005/.clang-uml b/tests/t20005/.clang-uml
new file mode 100644
index 00000000..d6248303
--- /dev/null
+++ b/tests/t20005/.clang-uml
@@ -0,0 +1,14 @@
+compilation_database_dir: ..
+output_directory: puml
+diagrams:
+  t20005_sequence:
+    type: sequence
+    glob:
+      - ../../tests/t20005/t20005.cc
+    include:
+      namespaces:
+        - clanguml::t20005
+    using_namespace:
+      - clanguml::t20005
+    start_from:
+      - function: "clanguml::t20005::C<T>::c"
\ No newline at end of file
diff --git a/tests/t20005/t20005.cc b/tests/t20005/t20005.cc
new file mode 100644
index 00000000..de066173
--- /dev/null
+++ b/tests/t20005/t20005.cc
@@ -0,0 +1,21 @@
+namespace clanguml {
+namespace t20005 {
+
+template <typename T> struct A {
+    T a(T arg) { return arg; }
+};
+
+template <typename T> struct B {
+    T b(T arg) { return a_.a(arg); }
+
+    A<T> a_;
+};
+
+template <typename T> struct C {
+    T c(T arg) { return b_.b(arg); }
+
+    B<T> b_;
+};
+
+}
+}
\ No newline at end of file
diff --git a/tests/t20005/test_case.h b/tests/t20005/test_case.h
new file mode 100644
index 00000000..f2f6ef6a
--- /dev/null
+++ b/tests/t20005/test_case.h
@@ -0,0 +1,45 @@
+/**
+ * tests/t20005/test_case.h
+ *
+ * Copyright (c) 2021-2022 Bartek Kryza <bkryza@gmail.com>
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+TEST_CASE("t20005", "[test-case][sequence]")
+{
+    auto [config, db] = load_config("t20005");
+
+    auto diagram = config.diagrams["t20005_sequence"];
+
+    REQUIRE(diagram->name == "t20005_sequence");
+
+    auto model = generate_sequence_diagram(*db, diagram);
+
+    REQUIRE(model->name() == "t20005_sequence");
+
+    auto puml = generate_sequence_puml(diagram, *model);
+    AliasMatcher _A(puml);
+
+    REQUIRE_THAT(puml, StartsWith("@startuml"));
+    REQUIRE_THAT(puml, EndsWith("@enduml\n"));
+
+    
+    // Check if all calls exist
+    REQUIRE_THAT(puml, HasCall(_A("C<T>"), _A("B<T>"), "b"));
+    REQUIRE_THAT(puml, HasCall(_A("B<T>"), _A("A<T>"), "a"));
+
+
+    save_puml(
+        "./" + config.output_directory() + "/" + diagram->name + ".puml", puml);
+}
\ No newline at end of file
diff --git a/tests/test_cases.cc b/tests/test_cases.cc
index 84ec433d..0433f165 100644
--- a/tests/test_cases.cc
+++ b/tests/test_cases.cc
@@ -251,6 +251,7 @@ using namespace clanguml::test::matchers;
 #include "t20002/test_case.h"
 #include "t20003/test_case.h"
 #include "t20004/test_case.h"
+#include "t20005/test_case.h"
 
 ///
 /// Package diagram tests
diff --git a/tests/test_cases.yaml b/tests/test_cases.yaml
index e10d342d..a78044a6 100644
--- a/tests/test_cases.yaml
+++ b/tests/test_cases.yaml
@@ -160,6 +160,9 @@ test_cases:
     - name: t20004
       title: Function template instantiation sequence diagram test case
       description:
+    - name: t20005
+      title: Class template basic sequence diagram
+      description:
   Package diagrams:
     - name: t30001
       title: Basic package diagram test case
diff --git a/util/templates/test_cases/.clang-uml b/util/templates/test_cases/.clang-uml
index 4e1e2749..63e89fab 100644
--- a/util/templates/test_cases/.clang-uml
+++ b/util/templates/test_cases/.clang-uml
@@ -7,4 +7,6 @@ diagrams:
       - ../../tests/{{ name }}/{{ name }}.cc
     include:
       namespaces:
-        - clanguml::{{ name }}
\ No newline at end of file
+        - clanguml::{{ name }}
+    using_namespace:
+      - clanguml::{{ name }}
\ No newline at end of file