diff --git a/src/sequence_diagram/visitor/translation_unit_visitor.cc b/src/sequence_diagram/visitor/translation_unit_visitor.cc
index 0e488c93..ad4fbf55 100644
--- a/src/sequence_diagram/visitor/translation_unit_visitor.cc
+++ b/src/sequence_diagram/visitor/translation_unit_visitor.cc
@@ -1301,7 +1301,7 @@ translation_unit_visitor::create_class_model(clang::CXXRecordDecl *cls)
             c.set_namespace(ns);
             c.set_id(common::to_id(c.full_name(false)));
 
-            // Check if lambda is declared as an argument passed to a
+            // TODO: Check if lambda is declared as an argument passed to a
             // function/method call
         }
         else {
@@ -2079,8 +2079,9 @@ std::string translation_unit_visitor::make_lambda_name(
     const auto location = cls->getLocation();
     const auto file_line = source_manager().getSpellingLineNumber(location);
     const auto file_column = source_manager().getSpellingColumnNumber(location);
-    const std::string file_name =
-        util::split(source_manager().getFilename(location).str(), "/").back();
+    const std::string file_name = std::filesystem::relative(
+        source_manager().getFilename(location).str(), config().relative_to())
+                                      .string();
 
     if (context().caller_id() != 0 &&
         get_participant(context().caller_id()).has_value()) {
diff --git a/tests/t20012/test_case.h b/tests/t20012/test_case.h
index e639dd23..d940d6e8 100644
--- a/tests/t20012/test_case.h
+++ b/tests/t20012/test_case.h
@@ -36,35 +36,43 @@ TEST_CASE("t20012", "[test-case][sequence]")
 
     // Check if all calls exist
     REQUIRE_THAT(puml,
-        HasCall(_A("tmain()"), _A("tmain()::(lambda t20012.cc:66:20)"),
+        HasCall(_A("tmain()"),
+            _A("tmain()::(lambda ../../tests/t20012/t20012.cc:66:20)"),
             "operator()()"));
-    REQUIRE_THAT(
-        puml, HasCall(_A("tmain()::(lambda t20012.cc:66:20)"), _A("A"), "a()"));
+    REQUIRE_THAT(puml,
+        HasCall(_A("tmain()::(lambda ../../tests/t20012/t20012.cc:66:20)"),
+            _A("A"), "a()"));
     REQUIRE_THAT(puml, HasCall(_A("A"), _A("A"), "aa()"));
     REQUIRE_THAT(puml, HasCall(_A("A"), _A("A"), "aaa()"));
 
-    REQUIRE_THAT(
-        puml, HasCall(_A("tmain()::(lambda t20012.cc:66:20)"), _A("B"), "b()"));
+    REQUIRE_THAT(puml,
+        HasCall(_A("tmain()::(lambda ../../tests/t20012/t20012.cc:66:20)"),
+            _A("B"), "b()"));
     REQUIRE_THAT(puml, HasCall(_A("B"), _A("B"), "bb()"));
     REQUIRE_THAT(puml, HasCall(_A("B"), _A("B"), "bbb()"));
 
-    REQUIRE_THAT(
-        puml, HasCall(_A("tmain()::(lambda t20012.cc:79:20)"), _A("C"), "c()"));
+    REQUIRE_THAT(puml,
+        HasCall(_A("tmain()::(lambda ../../tests/t20012/t20012.cc:79:20)"),
+            _A("C"), "c()"));
     REQUIRE_THAT(puml, HasCall(_A("C"), _A("C"), "cc()"));
     REQUIRE_THAT(puml, HasCall(_A("C"), _A("C"), "ccc()"));
     REQUIRE_THAT(puml,
-        HasCall(_A("tmain()::(lambda t20012.cc:79:20)"),
-            _A("tmain()::(lambda t20012.cc:66:20)"), "operator()()"));
+        HasCall(_A("tmain()::(lambda ../../tests/t20012/t20012.cc:79:20)"),
+            _A("tmain()::(lambda ../../tests/t20012/t20012.cc:66:20)"),
+            "operator()()"));
 
     REQUIRE_THAT(puml, HasCall(_A("C"), _A("C"), "ccc()"));
 
     REQUIRE_THAT(puml,
-        HasCall(_A("tmain()"), _A("R<R::(lambda t20012.cc:85:9)>"), "r()"));
+        HasCall(_A("tmain()"),
+            _A("R<R::(lambda ../../tests/t20012/t20012.cc:85:9)>"), "r()"));
     REQUIRE_THAT(puml,
-        HasCall(_A("R<R::(lambda t20012.cc:85:9)>"),
-            _A("tmain()::(lambda t20012.cc:85:9)"), "operator()()"));
-    REQUIRE_THAT(
-        puml, HasCall(_A("tmain()::(lambda t20012.cc:85:9)"), _A("C"), "c()"));
+        HasCall(_A("R<R::(lambda ../../tests/t20012/t20012.cc:85:9)>"),
+            _A("tmain()::(lambda ../../tests/t20012/t20012.cc:85:9)"),
+            "operator()()"));
+    REQUIRE_THAT(puml,
+        HasCall(_A("tmain()::(lambda ../../tests/t20012/t20012.cc:85:9)"),
+            _A("C"), "c()"));
 
     REQUIRE_THAT(puml, HasCall(_A("tmain()"), _A("D"), "add5(int)"));