diff --git a/src/sequence_diagram/visitor/translation_unit_visitor.cc b/src/sequence_diagram/visitor/translation_unit_visitor.cc
index 0328eb74..b5bfbdef 100644
--- a/src/sequence_diagram/visitor/translation_unit_visitor.cc
+++ b/src/sequence_diagram/visitor/translation_unit_visitor.cc
@@ -93,6 +93,8 @@ void translation_unit_visitor::process_activities(const cppast::cpp_function &e)
                 .lookup_definition(function_call.get_callee_id())
                 .value();
         m.to = cx::util::ns(callee) + "::" + callee.name();
+        if (callee.kind() == cpp_entity_kind::function_t)
+            m.to += "()";
 
         if (!ctx.config().should_include(m.to))
             continue;
diff --git a/tests/t20002/.clang-uml b/tests/t20002/.clang-uml
new file mode 100644
index 00000000..29d74b71
--- /dev/null
+++ b/tests/t20002/.clang-uml
@@ -0,0 +1,14 @@
+compilation_database_dir: ..
+output_directory: puml
+diagrams:
+  t20002_sequence:
+    type: sequence
+    glob:
+      - ../../tests/t20002/t20002.cc
+    include:
+      namespaces:
+        - clanguml::t20002
+    using_namespace:
+      - clanguml::t20002
+    start_from:
+      - function: "clanguml::t20002::m1()"
diff --git a/tests/t20002/t20002.cc b/tests/t20002/t20002.cc
new file mode 100644
index 00000000..9888c599
--- /dev/null
+++ b/tests/t20002/t20002.cc
@@ -0,0 +1,16 @@
+#include <algorithm>
+#include <numeric>
+#include <vector>
+
+namespace clanguml {
+namespace t20002 {
+
+void m4() { }
+
+void m3() { m4(); }
+
+void m2() { m3(); }
+
+void m1() { m2(); }
+}
+}
diff --git a/tests/t20002/test_case.h b/tests/t20002/test_case.h
new file mode 100644
index 00000000..01e80f02
--- /dev/null
+++ b/tests/t20002/test_case.h
@@ -0,0 +1,46 @@
+/**
+ * tests/t20002/test_case.cc
+ *
+ * Copyright (c) 2021 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("t20002", "[test-case][sequence]")
+{
+    auto [config, db] = load_config("t20002");
+
+    auto diagram = config.diagrams["t20002_sequence"];
+
+    REQUIRE(diagram->include.namespaces.size() == 1);
+    REQUIRE_THAT(diagram->include.namespaces,
+        VectorContains(std::string{"clanguml::t20002"}));
+
+    REQUIRE(diagram->name == "t20002_sequence");
+
+    auto model = generate_sequence_diagram(db, diagram);
+
+    REQUIRE(model.name == "t20002_sequence");
+
+    auto puml = generate_sequence_puml(diagram, model);
+
+    REQUIRE_THAT(puml, StartsWith("@startuml"));
+    REQUIRE_THAT(puml, EndsWith("@enduml\n"));
+
+    REQUIRE_THAT(puml, HasFunctionCall("m1", "m2"));
+    REQUIRE_THAT(puml, HasFunctionCall("m2", "m3"));
+    REQUIRE_THAT(puml, HasFunctionCall("m3", "m4"));
+
+    save_puml(
+        "./" + config.output_directory + "/" + diagram->name + ".puml", puml);
+}
diff --git a/tests/test_cases.cc b/tests/test_cases.cc
index 999f6828..2e3dc9b5 100644
--- a/tests/test_cases.cc
+++ b/tests/test_cases.cc
@@ -145,6 +145,7 @@ using namespace clanguml::test::matchers;
 // Sequence diagram tests
 //
 #include "t20001/test_case.h"
+#include "t20002/test_case.h"
 
 //
 // Other tests (e.g. configuration file)
diff --git a/tests/test_cases.h b/tests/test_cases.h
index 625ad19d..12088b96 100644
--- a/tests/test_cases.h
+++ b/tests/test_cases.h
@@ -127,6 +127,15 @@ ContainsMatcher HasCall(std::string const &from, std::string const &message,
             caseSensitivity));
 }
 
+ContainsMatcher HasFunctionCall(std::string const &from,
+    std::string const &message,
+    CaseSensitive::Choice caseSensitivity = CaseSensitive::Yes)
+{
+    return ContainsMatcher(CasedString(
+        fmt::format("\"{}()\" -> \"{}()\" : {}()", from, message, message),
+        caseSensitivity));
+}
+
 ContainsMatcher HasCall(std::string const &from, std::string const &to,
     std::string const &message,
     CaseSensitive::Choice caseSensitivity = CaseSensitive::Yes)
diff --git a/tests/test_cases.yaml b/tests/test_cases.yaml
index df851df1..9989b495 100644
--- a/tests/test_cases.yaml
+++ b/tests/test_cases.yaml
@@ -101,7 +101,10 @@ test_cases:
       description:
   Sequence diagrams:
     - name: t20001
-      title: Basic sequence diagram
+      title: Basic sequence diagram test case
+      description:
+    - name: t20002
+      title: Free function sequence diagram test case
       description:
   Configuration diagrams:
     - name: t90000