diff --git a/src/sequence_diagram/model/diagram.cc b/src/sequence_diagram/model/diagram.cc
index 6f6616b6..a660adfd 100644
--- a/src/sequence_diagram/model/diagram.cc
+++ b/src/sequence_diagram/model/diagram.cc
@@ -85,6 +85,11 @@ void diagram::print() const
         LOG_DBG("   Activity id={}, from={}:", act.from,
             from_activity.full_name(false));
         for (const auto &message : act.messages) {
+            if (participants.find(message.from) == participants.end())
+                continue;
+            if (participants.find(message.to) == participants.end())
+                continue;
+
             const auto &from_participant = *participants.at(message.from);
             const auto &to_participant = *participants.at(message.to);
 
diff --git a/tests/t20010/.clang-uml b/tests/t20010/.clang-uml
new file mode 100644
index 00000000..55f2dd81
--- /dev/null
+++ b/tests/t20010/.clang-uml
@@ -0,0 +1,14 @@
+compilation_database_dir: ..
+output_directory: puml
+diagrams:
+  t20010_sequence:
+    type: sequence
+    glob:
+      - ../../tests/t20010/t20010.cc
+    include:
+      namespaces:
+        - clanguml::t20010
+    using_namespace:
+      - clanguml::t20010
+    start_from:
+      - function: "clanguml::t20010::tmain()"
\ No newline at end of file
diff --git a/tests/t20010/t20010.cc b/tests/t20010/t20010.cc
new file mode 100644
index 00000000..3b8745cd
--- /dev/null
+++ b/tests/t20010/t20010.cc
@@ -0,0 +1,39 @@
+#include <array>
+#include <map>
+#include <memory>
+#include <vector>
+
+namespace clanguml {
+namespace t20010 {
+
+struct A {
+    void a1() { }
+    void a2() { }
+    void a3() { }
+    void a4() { }
+};
+
+template <typename T> struct B {
+    void b1() { a_.a1(); }
+    void b2() { avector_.front().a2(); }
+    void b3() { aptrvector_.front()->a3(); }
+    void b4() { amap_.at(0).a4(); }
+
+    A a_;
+    std::vector<A> avector_;
+    std::vector<std::unique_ptr<A>> aptrvector_;
+    std::map<T, A> amap_;
+};
+
+void tmain()
+{
+    B<int> b;
+
+    b.b1();
+    b.b2();
+    b.b3();
+    b.b4();
+}
+
+}
+}
\ No newline at end of file
diff --git a/tests/t20010/test_case.h b/tests/t20010/test_case.h
new file mode 100644
index 00000000..b2be4711
--- /dev/null
+++ b/tests/t20010/test_case.h
@@ -0,0 +1,52 @@
+/**
+ * tests/t20010/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("t20010", "[test-case][sequence]")
+{
+    auto [config, db] = load_config("t20010");
+
+    auto diagram = config.diagrams["t20010_sequence"];
+
+    REQUIRE(diagram->name == "t20010_sequence");
+
+    auto model = generate_sequence_diagram(*db, diagram);
+
+    REQUIRE(model->name() == "t20010_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<int>"), "b1"));
+    REQUIRE_THAT(puml, HasCall(_A("B<int>"), _A("A"), "a1"));
+
+    REQUIRE_THAT(puml, HasCall(_A("tmain()"), _A("B<int>"), "b2"));
+    REQUIRE_THAT(puml, HasCall(_A("B<int>"), _A("A"), "a2"));
+
+    REQUIRE_THAT(puml, HasCall(_A("tmain()"), _A("B<int>"), "b3"));
+    REQUIRE_THAT(puml, HasCall(_A("B<int>"), _A("A"), "a3"));
+
+    REQUIRE_THAT(puml, HasCall(_A("tmain()"), _A("B<int>"), "b4"));
+    REQUIRE_THAT(puml, HasCall(_A("B<int>"), _A("A"), "a4"));
+
+    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 1103de0a..96a4d2f6 100644
--- a/tests/test_cases.cc
+++ b/tests/test_cases.cc
@@ -256,6 +256,7 @@ using namespace clanguml::test::matchers;
 #include "t20007/test_case.h"
 #include "t20008/test_case.h"
 #include "t20009/test_case.h"
+#include "t20010/test_case.h"
 
 ///
 /// Package diagram tests
diff --git a/tests/test_cases.yaml b/tests/test_cases.yaml
index 4fa3d254..7b1c8a53 100644
--- a/tests/test_cases.yaml
+++ b/tests/test_cases.yaml
@@ -175,6 +175,9 @@ test_cases:
     - name: t20009
       title: Smart pointer dereference call expression test case
       description:
+    - name: t20010
+      title: Container sequence diagram test case
+      description:
   Package diagrams:
     - name: t30001
       title: Basic package diagram test case