diff --git a/src/test/libslic3r/test_3mf.cpp b/src/test/libslic3r/test_3mf.cpp
index 09384d790..23cd24ee7 100644
--- a/src/test/libslic3r/test_3mf.cpp
+++ b/src/test/libslic3r/test_3mf.cpp
@@ -1,6 +1,5 @@
 #include <catch.hpp>
 #include <test_options.hpp>
-#include <string>
 #include "Model.hpp"
 #include "TMF.hpp"
 
@@ -9,9 +8,9 @@ using namespace Slic3r;
 
 SCENARIO("Reading 3mf file") {
     GIVEN("umlauts in the path of the file") {
-         auto model {new Slic3r::Model()};
+        auto model {new Slic3r::Model()};
         WHEN("3mf model is read") {
-            auto ret = Slic3r::IO::TMF::read(std::string(testfile_dir) +"test_3mf/Geräte/box.3mf",model);
+            auto ret = Slic3r::IO::TMF::read(testfile("test_3mf/Geräte/box.3mf"),model);
             THEN("read should not return 0") {
                 REQUIRE(ret == 1);
             }