diff --git a/Makefile b/Makefile
index d02767153..6b18ed82b 100644
--- a/Makefile
+++ b/Makefile
@@ -268,5 +268,5 @@ serve_header:
 
 reuse:
 	pipx run reuse addheader --recursive single_include include -tjson --license MIT --copyright "Niels Lohmann <https://nlohmann.me>" --year "2013-2022"
-	pipx run reuse addheader tests/benchmarks/src/benchmarks.cpp tests/src/* -tjson_support --license MIT --copyright "Niels Lohmann <https://nlohmann.me>" --year "2013-2022"
+	pipx run reuse addheader tests/benchmarks/src/benchmarks.cpp tests/src/*.cpp tests/src/*.hpp tests/abi/**/*.cpp tests/abi/**/*.hpp -tjson_support --license MIT --copyright "Niels Lohmann <https://nlohmann.me>" --year "2013-2022"
 	pipx run reuse lint
diff --git a/tests/abi/diag/diag.cpp b/tests/abi/diag/diag.cpp
index c36ca2bab..6e9fa011a 100644
--- a/tests/abi/diag/diag.cpp
+++ b/tests/abi/diag/diag.cpp
@@ -1,3 +1,11 @@
+//     __ _____ _____ _____
+//  __|  |   __|     |   | |  JSON for Modern C++ (supporting code)
+// |  |  |__   |  |  | | | |  version 3.10.5
+// |_____|_____|_____|_|___|  https://github.com/nlohmann/json
+//
+// SPDX-FileCopyrightText: 2013-2022 Niels Lohmann <https://nlohmann.me>
+// SPDX-License-Identifier: MIT
+
 #include "doctest_compatibility.h"
 
 #include "diag.hpp"
diff --git a/tests/abi/diag/diag.hpp b/tests/abi/diag/diag.hpp
index 69c476da1..480cf008b 100644
--- a/tests/abi/diag/diag.hpp
+++ b/tests/abi/diag/diag.hpp
@@ -1,3 +1,11 @@
+//     __ _____ _____ _____
+//  __|  |   __|     |   | |  JSON for Modern C++ (supporting code)
+// |  |  |__   |  |  | | | |  version 3.10.5
+// |_____|_____|_____|_|___|  https://github.com/nlohmann/json
+//
+// SPDX-FileCopyrightText: 2013-2022 Niels Lohmann <https://nlohmann.me>
+// SPDX-License-Identifier: MIT
+
 #pragma once
 
 #include <cstddef>
diff --git a/tests/abi/diag/diag_off.cpp b/tests/abi/diag/diag_off.cpp
index a9fcc92ed..353716111 100644
--- a/tests/abi/diag/diag_off.cpp
+++ b/tests/abi/diag/diag_off.cpp
@@ -1,3 +1,11 @@
+//     __ _____ _____ _____
+//  __|  |   __|     |   | |  JSON for Modern C++ (supporting code)
+// |  |  |__   |  |  | | | |  version 3.10.5
+// |_____|_____|_____|_|___|  https://github.com/nlohmann/json
+//
+// SPDX-FileCopyrightText: 2013-2022 Niels Lohmann <https://nlohmann.me>
+// SPDX-License-Identifier: MIT
+
 #undef JSON_DIAGNOSTICS
 #define JSON_DIAGNOSTICS 0
 #include <nlohmann/json.hpp>
diff --git a/tests/abi/diag/diag_on.cpp b/tests/abi/diag/diag_on.cpp
index f1c043aa0..f5b492eea 100644
--- a/tests/abi/diag/diag_on.cpp
+++ b/tests/abi/diag/diag_on.cpp
@@ -1,3 +1,11 @@
+//     __ _____ _____ _____
+//  __|  |   __|     |   | |  JSON for Modern C++ (supporting code)
+// |  |  |__   |  |  | | | |  version 3.10.5
+// |_____|_____|_____|_|___|  https://github.com/nlohmann/json
+//
+// SPDX-FileCopyrightText: 2013-2022 Niels Lohmann <https://nlohmann.me>
+// SPDX-License-Identifier: MIT
+
 #undef JSON_DIAGNOSTICS
 #define JSON_DIAGNOSTICS 1
 #include <nlohmann/json.hpp>
diff --git a/tests/abi/inline_ns/use_current.cpp b/tests/abi/inline_ns/use_current.cpp
index 84dcb68ec..df3b1abd2 100644
--- a/tests/abi/inline_ns/use_current.cpp
+++ b/tests/abi/inline_ns/use_current.cpp
@@ -1,3 +1,11 @@
+//     __ _____ _____ _____
+//  __|  |   __|     |   | |  JSON for Modern C++ (supporting code)
+// |  |  |__   |  |  | | | |  version 3.10.5
+// |_____|_____|_____|_|___|  https://github.com/nlohmann/json
+//
+// SPDX-FileCopyrightText: 2013-2022 Niels Lohmann <https://nlohmann.me>
+// SPDX-License-Identifier: MIT
+
 #include "doctest_compatibility.h"
 
 #include <nlohmann/json.hpp>
diff --git a/tests/abi/inline_ns/use_v3_10_5.cpp b/tests/abi/inline_ns/use_v3_10_5.cpp
index 82c89e751..63a14d134 100644
--- a/tests/abi/inline_ns/use_v3_10_5.cpp
+++ b/tests/abi/inline_ns/use_v3_10_5.cpp
@@ -1,3 +1,11 @@
+//     __ _____ _____ _____
+//  __|  |   __|     |   | |  JSON for Modern C++ (supporting code)
+// |  |  |__   |  |  | | | |  version 3.10.5
+// |_____|_____|_____|_|___|  https://github.com/nlohmann/json
+//
+// SPDX-FileCopyrightText: 2013-2022 Niels Lohmann <https://nlohmann.me>
+// SPDX-License-Identifier: MIT
+
 #include "doctest_compatibility.h"
 
 #include <nlohmann/json_v3_10_5.hpp>