diff --git a/test/unit/endianness_test.cpp b/test/unit/endianness_test.cpp
index 4e2d584..9df1afb 100644
--- a/test/unit/endianness_test.cpp
+++ b/test/unit/endianness_test.cpp
@@ -1,4 +1,4 @@
-/* Copyright 2017, Michele Santullo
+/* Copyright 2016-2018 Michele Santullo
  * This file is part of "duckhandy".
  *
  * "duckhandy" is free software: you can redistribute it and/or modify
diff --git a/test/unit/int_conv_test.cpp b/test/unit/int_conv_test.cpp
index feb8741..ff3c5dd 100644
--- a/test/unit/int_conv_test.cpp
+++ b/test/unit/int_conv_test.cpp
@@ -1,4 +1,4 @@
-/* Copyright 2017, Michele Santullo
+/* Copyright 2016-2018 Michele Santullo
  * This file is part of "duckhandy".
  *
  * "duckhandy" is free software: you can redistribute it and/or modify
diff --git a/test/unit/lexical_cast_test.cpp b/test/unit/lexical_cast_test.cpp
index 4dd5c64..422dab7 100644
--- a/test/unit/lexical_cast_test.cpp
+++ b/test/unit/lexical_cast_test.cpp
@@ -1,4 +1,4 @@
-/* Copyright 2017, Michele Santullo
+/* Copyright 2016-2018 Michele Santullo
  * This file is part of "duckhandy".
  *
  * "duckhandy" is free software: you can redistribute it and/or modify
diff --git a/test/unit/main.cpp b/test/unit/main.cpp
index d3bb9b6..a003679 100644
--- a/test/unit/main.cpp
+++ b/test/unit/main.cpp
@@ -1,4 +1,4 @@
-/* Copyright 2017, Michele Santullo
+/* Copyright 2016-2018 Michele Santullo
  * This file is part of "duckhandy".
  *
  * "duckhandy" is free software: you can redistribute it and/or modify