diff --git a/src/unittest/CMakeLists.txt b/src/unittest/CMakeLists.txt
index 9ac275d7f..3acbf7012 100644
--- a/src/unittest/CMakeLists.txt
+++ b/src/unittest/CMakeLists.txt
@@ -58,6 +58,8 @@ set (UNITTEST_CLIENT_SRCS
 	${CMAKE_CURRENT_SOURCE_DIR}/test_eventmanager.cpp
 	${CMAKE_CURRENT_SOURCE_DIR}/test_gameui.cpp
 	${CMAKE_CURRENT_SOURCE_DIR}/test_irr_gltf_mesh_loader.cpp
+	${CMAKE_CURRENT_SOURCE_DIR}/test_irr_x_mesh_loader.cpp
+	${CMAKE_CURRENT_SOURCE_DIR}/test_irr_matrix4.cpp
 	${CMAKE_CURRENT_SOURCE_DIR}/test_mesh_compare.cpp
 	${CMAKE_CURRENT_SOURCE_DIR}/test_keycode.cpp
 	PARENT_SCOPE)
diff --git a/src/unittest/test_irr_x_mesh_loader.cpp b/src/unittest/test_irr_x_mesh_loader.cpp
new file mode 100644
index 000000000..555bfb2b8
--- /dev/null
+++ b/src/unittest/test_irr_x_mesh_loader.cpp
@@ -0,0 +1,84 @@
+// Luanti
+// SPDX-License-Identifier: LGPL-2.1-or-later
+
+#include "catch_amalgamated.hpp"
+#include "content/subgames.h"
+#include "filesys.h"
+
+#include "irrlichttypes.h"
+#include "irr_ptr.h"
+
+#include "EDriverTypes.h"
+#include "IFileSystem.h"
+#include "IReadFile.h"
+#include "ISceneManager.h"
+#include "SkinnedMesh.h"
+#include "irrlicht.h"
+
+#include "catch.h"
+#include "matrix4.h"
+
+TEST_CASE("x") {
+
+const auto gamespec = findSubgame("devtest");
+
+if (!gamespec.isValid())
+	SKIP();
+
+irr::SIrrlichtCreationParameters p;
+p.DriverType = video::EDT_NULL;
+auto *driver = irr::createDeviceEx(p);
+REQUIRE(driver);
+
+auto *smgr = driver->getSceneManager();
+const auto loadMesh = [&] (const io::path& filepath) {
+	irr_ptr<io::IReadFile> file(driver->getFileSystem()->createAndOpenFile(filepath));
+	REQUIRE(file);
+	return smgr->getMesh(file.get());
+};
+
+const static auto model_stem = gamespec.gamemods_path +
+		DIR_DELIM + "testentities" + DIR_DELIM + "models" + DIR_DELIM + "testentities_";
+
+SECTION("cool guy") {
+	const auto *mesh = dynamic_cast<irr::scene::SkinnedMesh*>(loadMesh(model_stem + "cool_guy.x"));
+	REQUIRE(mesh);
+	REQUIRE(mesh->getMeshBufferCount() == 1);
+
+	auto getJoint = [&](auto name) {
+		return mesh->getAllJoints()[mesh->getJointNumber(name).value()];
+	};
+
+	const auto *root = getJoint("Root");
+	const auto *armature = getJoint("Armature");
+	const auto *armature_body = getJoint("Armature_body");
+	const auto *armature_arm_r = getJoint("Armature_arm_r");
+
+
+	SECTION("local matrices are correct") {
+		REQUIRE(root->LocalMatrix.equals(core::IdentityMatrix));
+		REQUIRE(armature->LocalMatrix.equals(core::IdentityMatrix));
+		REQUIRE(armature_body->LocalMatrix.equals(core::matrix4(
+			-1,0,0,0,
+			0,0,1,0,
+			0,1,0,0,
+			0,2.571201,0,1
+		)));
+		REQUIRE(armature_arm_r->LocalMatrix.equals(core::matrix4(
+			-0.047733,0.997488,-0.05233,0,
+			0.901521,0.020464,-0.432251,0,
+			-0.430095,-0.067809,-0.900233,
+			0,-0.545315,0,1,1
+		)));
+	}
+
+	SECTION("global matrices are correct") {
+		REQUIRE(armature_body->GlobalMatrix.equals(armature_body->LocalMatrix));
+		REQUIRE(armature_arm_r->GlobalMatrix.equals(
+			armature_body->GlobalMatrix * armature_arm_r->LocalMatrix));
+	}
+}
+
+driver->closeDevice();
+driver->drop();
+}