diff --git a/.github/workflows/cibuild.yml b/.github/workflows/cibuild.yml
index 3d751c56528..37dc21aa697 100644
--- a/.github/workflows/cibuild.yml
+++ b/.github/workflows/cibuild.yml
@@ -152,6 +152,10 @@ jobs:
       id: cmake-build
       run: cmake --build build --config ${{ matrix.configuration }} --parallel ${{ matrix.platform.threads || 4 }}
 
+    - name: Run CTest
+      working-directory: build
+      run: ctest --config ${{ matrix.configuration }} --parallel ${{ matrix.platform.threads || 4 }} --output-on-failure --schedule-random --no-tests=error
+
     - name: Make package
       if: ${{ steps.cmake-build.outcome == 'success' }}
       id: make-package
@@ -233,3 +237,16 @@ jobs:
         shutdown_vm: false
         sync_files: false
         run: cmake --build build --config ${{ matrix.Configuration }} --parallel 4
+
+    - name: Run CTest
+      uses: cross-platform-actions/action@v0.23.0
+      with:
+        operating_system: ${{ matrix.platform.os }}
+        architecture: ${{ matrix.platform.arch }}
+        version: ${{ matrix.platform.os-version }}
+        cpu_count: 4
+        memory: 13G
+        environment_variables: CFLAGS CXXFLAGS
+        shutdown_vm: false
+        sync_files: false
+        run: ctest -C ${{ matrix.Configuration }} --parallel 4 --output-on-failure --schedule-random --no-tests=error
diff --git a/.gitmodules b/.gitmodules
index d653b46d1ba..62beff6839d 100644
--- a/.gitmodules
+++ b/.gitmodules
@@ -46,3 +46,7 @@
 [submodule "Externals/xrLuaFix"]
 	path = Externals/xrLuaFix
 	url = https://github.com/OpenXRay/xrLuaFix.git
+[submodule "Externals/doctest"]
+	path = Externals/doctest
+	url = https://github.com/doctest/doctest.git
+	branch = master
diff --git a/CMakeLists.txt b/CMakeLists.txt
index cfa8d64409b..53e5ae289cc 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -139,12 +139,16 @@ if (CMAKE_CXX_COMPILER_ID MATCHES "Clang" AND NOT XRAY_USE_DEFAULT_CXX_LIB)
 
     if (XRAY_CXX_LIB STREQUAL "libstdc++")
         add_compile_options(-stdlib=libstdc++)
+        add_link_options(-stdlib=libstdc++)
     elseif (XRAY_CXX_LIB STREQUAL "libc++")
         add_compile_options(-stdlib=libc++)
+        add_link_options(-stdlib=libc++)
         if (CMAKE_SYSTEM_NAME STREQUAL "FreeBSD")
             add_compile_options(-lcxxrt)
+            add_link_options(-lcxxrt)
         else()
             add_compile_options(-lc++abi)
+            add_link_options(-lc++abi)
         endif()
     endif()
 endif()
@@ -290,6 +294,13 @@ add_subdirectory(src)
 add_subdirectory(res)
 add_subdirectory(misc)
 
+# Tests
+option(BUILD_TESTS "Build tests" ON)
+if (BUILD_TESTS)
+    include(CTest)
+    add_subdirectory(tests)
+endif()
+
 get_property(LIB64 GLOBAL PROPERTY FIND_LIBRARY_USE_LIB64_PATHS)
 
 if ("${LIB64}" STREQUAL "TRUE")
diff --git a/Externals/CMakeLists.txt b/Externals/CMakeLists.txt
index 6ee73375534..f16a53b225f 100644
--- a/Externals/CMakeLists.txt
+++ b/Externals/CMakeLists.txt
@@ -16,6 +16,7 @@ add_subdirectory(OPCODE)
 add_subdirectory(ode)
 #add_subdirectory(NVTT)
 add_subdirectory(imgui-proj)
+add_subdirectory(doctest EXCLUDE_FROM_ALL)
 
 if (NOT TARGET xrLuabind)
     message(FATAL_ERROR
diff --git a/Externals/doctest b/Externals/doctest
new file mode 160000
index 00000000000..ae7a13539fb
--- /dev/null
+++ b/Externals/doctest
@@ -0,0 +1 @@
+Subproject commit ae7a13539fb71f270b87eb2e874fbac80bc8dda2
diff --git a/tests/CMakeLists.txt b/tests/CMakeLists.txt
new file mode 100644
index 00000000000..bef9148cd2f
--- /dev/null
+++ b/tests/CMakeLists.txt
@@ -0,0 +1 @@
+add_subdirectory(xrCore)
diff --git a/tests/xrCore/CMakeLists.txt b/tests/xrCore/CMakeLists.txt
new file mode 100644
index 00000000000..dd030e23d19
--- /dev/null
+++ b/tests/xrCore/CMakeLists.txt
@@ -0,0 +1,13 @@
+add_executable(
+    xrCoreTests
+    main.cpp
+    xr_ini_test.cpp)
+
+target_link_libraries(xrCoreTests xrCore doctest::doctest)
+target_include_directories(xrCoreTests PRIVATE "${CMAKE_SOURCE_DIR}/src")
+add_test(NAME xrCoreTests COMMAND xrCoreTests)
+# https://github.com/doctest/doctest/blob/master/doc/markdown/configuration.md
+target_compile_definitions(xrCoreTests PRIVATE
+    DOCTEST_CONFIG_TREAT_CHAR_STAR_AS_STRING
+    DOCTEST_CONFIG_SUPER_FAST_ASSERTS
+)
diff --git a/tests/xrCore/main.cpp b/tests/xrCore/main.cpp
new file mode 100644
index 00000000000..9f883e65bf9
--- /dev/null
+++ b/tests/xrCore/main.cpp
@@ -0,0 +1,15 @@
+#define DOCTEST_CONFIG_IMPLEMENT
+#include <doctest/doctest.h>
+
+#include <Common/Platform.hpp>
+#include <xrCore/xrCore.h>
+
+int main(int argc, char** argv)
+{
+    doctest::Context context;
+    context.applyCommandLine(argc, argv);
+
+    Memory._initialize();
+
+    return context.run();
+}
diff --git a/tests/xrCore/xr_ini_test.cpp b/tests/xrCore/xr_ini_test.cpp
new file mode 100644
index 00000000000..77f5ee32c9a
--- /dev/null
+++ b/tests/xrCore/xr_ini_test.cpp
@@ -0,0 +1,94 @@
+#include <doctest/doctest.h>
+
+#include <Common/Platform.hpp>
+#include <xrCore/xrCore.h>
+#include <xrCore/xr_types.h>
+
+#include <xrCore/xr_ini.h>
+
+CInifile read_from_string(pcstr str, CInifile::allow_include_func_t allow_include = nullptr)
+{
+    IReader reader = IReader(const_cast<pstr>(str), xr_strlen(str));
+    return CInifile(&reader, "test.ini", allow_include);
+}
+
+TEST_CASE("parse empty file")
+{
+    CInifile ini = read_from_string("");
+
+    CHECK_EQ(ini.section_count(), 0);
+}
+
+TEST_CASE("parse empty section")
+{
+    CInifile ini = read_from_string("[a]");
+
+    CHECK_EQ(ini.section_count(), 1);
+    CHECK_UNARY(ini.section_exist("a"));
+}
+
+TEST_CASE("parse simple section")
+{
+    CInifile ini = read_from_string(
+        R"ini(
+[a]
+key = value
+)ini");
+
+    CHECK_UNARY(ini.section_exist("a"));
+    CHECK_UNARY(ini.line_exist("a", "key"));
+    CHECK_EQ(ini.read<pcstr>("a", "key"), "value");
+}
+
+TEST_CASE("parse integer value")
+{
+    CInifile ini = read_from_string(
+        R"ini(
+[a]
+key = 123
+)ini");
+
+    CHECK_UNARY(ini.section_exist("a"));
+    CHECK_UNARY(ini.line_exist("a", "key"));
+    CHECK_EQ(ini.read<u32>("a", "key"), 123);
+}
+
+TEST_CASE("Parse float value")
+{
+    CInifile ini = read_from_string(
+        R"ini(
+[a]
+key = 123.456
+)ini");
+
+    CHECK_UNARY(ini.section_exist("a"));
+    CHECK_UNARY(ini.line_exist("a", "key"));
+    CHECK_EQ(ini.read<f32>("a", "key"), 123.456f);
+}
+
+TEST_CASE("Parse quoted value")
+{
+    CInifile ini = read_from_string(
+        R"ini(
+[a]
+key = "value"
+)ini");
+
+    CHECK_UNARY(ini.section_exist("a"));
+    CHECK_UNARY(ini.line_exist("a", "key"));
+    CHECK_EQ(ini.read<pcstr>("a", "key"), "\"value\"");
+}
+
+TEST_CASE("Parse multiline value")
+{
+    CInifile ini = read_from_string(
+        R"ini(
+[a]
+key = "multiline
+value"
+)ini");
+
+    CHECK_UNARY(ini.section_exist("a"));
+    CHECK_UNARY(ini.line_exist("a", "key"));
+    CHECK_EQ(ini.read<pcstr>("a", "key"), "\"multiline\r\nvalue\"");
+}