diff --git a/apps/mwiniimporter_tests/CMakeLists.txt b/apps/mwiniimporter_tests/CMakeLists.txt
index 0d58b0544c..eb6a191cd3 100644
--- a/apps/mwiniimporter_tests/CMakeLists.txt
+++ b/apps/mwiniimporter_tests/CMakeLists.txt
@@ -9,7 +9,8 @@ openmw_add_executable(openmw-iniimporter-tests ${INIIMPORTER_TESTS_SRC_FILES})
 target_include_directories(openmw-iniimporter-tests SYSTEM PRIVATE ${GTEST_INCLUDE_DIRS})
 target_include_directories(openmw-iniimporter-tests SYSTEM PRIVATE ${GMOCK_INCLUDE_DIRS})
 
-add_definitions(-DCMAKE_BINARY_DIR="${CMAKE_BINARY_DIR}")
+#add_definitions(-DCMAKE_BINARY_DIR="${CMAKE_BINARY_DIR}")
+target_compile_definitions(openmw-iniimporter-tests PRIVATE CMAKE_BINARY_DIR=u8"${CMAKE_BINARY_DIR}")
 
 target_link_libraries(openmw-iniimporter-tests PRIVATE
     GTest::GTest
diff --git a/apps/mwiniimporter_tests/main.cpp b/apps/mwiniimporter_tests/main.cpp
index 6aac3fc368..f6cd2d2b37 100644
--- a/apps/mwiniimporter_tests/main.cpp
+++ b/apps/mwiniimporter_tests/main.cpp
@@ -1,3 +1,4 @@
+#include <components/misc/strings/conversion.hpp>
 #include <filesystem>
 #include <fstream>
 #include <gtest/gtest.h>
@@ -35,10 +36,10 @@ Archive 1=game2.bsa
     tempFile.close();
     std::filesystem::path tempCfgFile = std::filesystem::temp_directory_path() / (param.fileName + ".cfg");
 
-    std::stringstream cmd;
-    cmd << CMAKE_BINARY_DIR << "/openmw-iniimporter -i " << tempIniFile << " -c " << tempCfgFile;
+    std::basic_stringstream<char8_t> cmd;
+    cmd << CMAKE_BINARY_DIR << u8"/openmw-iniimporter -i " << tempIniFile << u8" -c " << tempCfgFile;
 
-    int ret = std::system(cmd.str().c_str());
+    int ret = std::system(Misc::StringUtils::u8StringToString(std::u8string(cmd.str())).c_str());
     ASSERT_EQ(ret, 0);
 
     // Verify the cfg file was created and has the expected contents