diff --git a/irr/include/matrix4.h b/irr/include/matrix4.h
index c25a3b5d6..5acce32e7 100644
--- a/irr/include/matrix4.h
+++ b/irr/include/matrix4.h
@@ -1661,7 +1661,7 @@ inline void CMatrix4<T>::getTransposed(CMatrix4<T> &o) const
 }
 
 template <class T>
-std::ostream& operator<<(std::ostream& os, const CMatrix4<T>& matrix)
+inline std::ostream& operator<<(std::ostream& os, const CMatrix4<T>& matrix)
 {
 	os << "(\n";
 	for (int row = 0; row < 4; ++row) {
diff --git a/irr/include/quaternion.h b/irr/include/quaternion.h
index f3ddc5bd6..e99e721e2 100644
--- a/irr/include/quaternion.h
+++ b/irr/include/quaternion.h
@@ -217,7 +217,7 @@ public:
 	f32 W; // real part
 };
 
-std::ostream& operator<<(std::ostream& os, const quaternion& q)
+inline std::ostream& operator<<(std::ostream& os, const quaternion& q)
 {
 	os << q.X << "\t" << q.Y << "\t" << q.Z << "\t" << q.W;
 	return os;
diff --git a/src/script/lua_api/l_matrix4.cpp b/src/script/lua_api/l_matrix4.cpp
index 56c447aba..23bc39957 100644
--- a/src/script/lua_api/l_matrix4.cpp
+++ b/src/script/lua_api/l_matrix4.cpp
@@ -2,21 +2,20 @@
 // SPDX-License-Identifier: LGPL-2.1-or-later
 // Copyright (C) 2025 Lars Müller
 
-#include "common/c_converter.h"
 #include "irrTypes.h"
 #include "irr_v3d.h"
-#include "lua_api/l_rotation.h"
 #include "matrix4.h"
+#include "quaternion.h"
 
 #include "lua_api/l_matrix4.h"
-#include "common/c_packer.h"
+#include "lua_api/l_rotation.h"
 #include "lua_api/l_internal.h"
-#include "quaternion.h"
+#include "common/c_packer.h"
+#include "common/c_converter.h"
 
 #include <cmath>
 #include <lauxlib.h>
 #include <lua.h>
-#include <luajit-2.1/lauxlib.h>
 #include <sstream>
 
 template<int MAX>
diff --git a/src/script/lua_api/l_matrix4.h b/src/script/lua_api/l_matrix4.h
index 3f44f8371..252c179a3 100644
--- a/src/script/lua_api/l_matrix4.h
+++ b/src/script/lua_api/l_matrix4.h
@@ -4,9 +4,9 @@
 
 #pragma once
 
-#include "lua_api/l_base.h"
 #include "matrix4.h"
-#include <lua.h>
+
+#include "lua_api/l_base.h"
 
 class LuaMatrix4 : public ModApiBase
 {
diff --git a/src/script/lua_api/l_rotation.h b/src/script/lua_api/l_rotation.h
index 458bbd78b..0212eeac4 100644
--- a/src/script/lua_api/l_rotation.h
+++ b/src/script/lua_api/l_rotation.h
@@ -5,9 +5,10 @@
 #pragma once
 
 #include "irr_v3d.h"
-#include "lua_api/l_base.h"
 #include "quaternion.h"
 
+#include "lua_api/l_base.h"
+
 class LuaRotation : public ModApiBase
 {
 private: