diff --git a/tests/t20015/.clang-uml b/tests/t20015/.clang-uml
new file mode 100644
index 00000000..231e9543
--- /dev/null
+++ b/tests/t20015/.clang-uml
@@ -0,0 +1,17 @@
+compilation_database_dir: ..
+output_directory: puml
+diagrams:
+  t20015_sequence:
+    type: sequence
+    glob:
+      - ../../tests/t20015/t20015.cc
+    include:
+      namespaces:
+        - clanguml::t20015
+    exclude:
+      namespaces:
+        - clanguml::t20015::detail
+    using_namespace:
+      - clanguml::t20015
+    start_from:
+      - function: "clanguml::t20015::tmain()"
\ No newline at end of file
diff --git a/tests/t20015/t20015.cc b/tests/t20015/t20015.cc
new file mode 100644
index 00000000..0c999632
--- /dev/null
+++ b/tests/t20015/t20015.cc
@@ -0,0 +1,39 @@
+#include <memory>
+
+namespace clanguml {
+namespace t20015 {
+
+namespace detail {
+class A {
+public:
+    void set_x(int x) { x_ = x; }
+    void set_y(int y) { y_ = y; }
+    void set_z(int z) { z_ = z; }
+
+private:
+    int x_;
+    int y_;
+    int z_;
+};
+}
+
+class B {
+public:
+    void setup_a(std::shared_ptr<detail::A> &a)
+    {
+        a->set_x(1);
+        a.get()->set_y(2);
+        (*a).set_z(3);
+    }
+};
+
+void tmain()
+{
+    auto a = std::make_shared<detail::A>();
+
+    B b;
+
+    b.setup_a(a);
+}
+}
+}
\ No newline at end of file
diff --git a/tests/t20015/test_case.h b/tests/t20015/test_case.h
new file mode 100644
index 00000000..54186b73
--- /dev/null
+++ b/tests/t20015/test_case.h
@@ -0,0 +1,51 @@
+/**
+ * tests/t20015/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("t20015", "[test-case][sequence]")
+{
+    auto [config, db] = load_config("t20015");
+
+    auto diagram = config.diagrams["t20015_sequence"];
+
+    REQUIRE(diagram->name == "t20015_sequence");
+
+    auto model = generate_sequence_diagram(*db, diagram);
+
+    REQUIRE(model->name() == "t20015_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("tmain()"), _A("B"), "setup_a(std::shared_ptr<detail::A> &)"));
+    REQUIRE_THAT(puml, !HasCall(_A("B"), _A("detail::A"), "set_x(int)"));
+    REQUIRE_THAT(puml, !HasCall(_A("B"), _A("detail::A"), "set_y(int)"));
+    REQUIRE_THAT(puml, !HasCall(_A("B"), _A("detail::A"), "set_z(int)"));
+
+    REQUIRE_THAT(puml, !HasCall(_A("B"), _A("B"), "set_x(int)"));
+    REQUIRE_THAT(puml, !HasCall(_A("B"), _A("B"), "set_y(int)"));
+    REQUIRE_THAT(puml, !HasCall(_A("B"), _A("B"), "set_z(int)"));
+
+    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 9e0486ea..fe09b0be 100644
--- a/tests/test_cases.cc
+++ b/tests/test_cases.cc
@@ -261,6 +261,7 @@ using namespace clanguml::test::matchers;
 #include "t20012/test_case.h"
 #include "t20013/test_case.h"
 #include "t20014/test_case.h"
+#include "t20015/test_case.h"
 
 ///
 /// Package diagram tests
diff --git a/tests/test_cases.yaml b/tests/test_cases.yaml
index 4f60cb43..a7c8d4db 100644
--- a/tests/test_cases.yaml
+++ b/tests/test_cases.yaml
@@ -190,6 +190,9 @@ test_cases:
     - name: t20014
       title: Multiple translation units sequence diagram test case
       description:
+    - name: t20015
+      title: Class exclusion by namespace in sequence diagram test case
+      description:
   Package diagrams:
     - name: t30001
       title: Basic package diagram test case