diff --git a/NOTICE b/NOTICE
index f3a42c2..47f09b6 100644
--- a/NOTICE
+++ b/NOTICE
@@ -1,4 +1,4 @@
-Copyright 2022 Input Output (Hong Kong) Ltd.
+Copyright 2022-2023 Input Output (Hong Kong) Ltd.
 
    Licensed under the Apache License, Version 2.0 (the "License");
    you may not use this file except in compliance with the License.
diff --git a/diff-containers/NOTICE b/diff-containers/NOTICE
index f3a42c2..47f09b6 100644
--- a/diff-containers/NOTICE
+++ b/diff-containers/NOTICE
@@ -1,4 +1,4 @@
-Copyright 2022 Input Output (Hong Kong) Ltd.
+Copyright 2022-2023 Input Output (Hong Kong) Ltd.
 
    Licensed under the Apache License, Version 2.0 (the "License");
    you may not use this file except in compliance with the License.
diff --git a/fingertree-rm/NOTICE b/fingertree-rm/NOTICE
index f3a42c2..47f09b6 100644
--- a/fingertree-rm/NOTICE
+++ b/fingertree-rm/NOTICE
@@ -1,4 +1,4 @@
-Copyright 2022 Input Output (Hong Kong) Ltd.
+Copyright 2022-2023 Input Output (Hong Kong) Ltd.
 
    Licensed under the Apache License, Version 2.0 (the "License");
    you may not use this file except in compliance with the License.
diff --git a/simple-semigroupoids/NOTICE b/simple-semigroupoids/NOTICE
index f3a42c2..47f09b6 100644
--- a/simple-semigroupoids/NOTICE
+++ b/simple-semigroupoids/NOTICE
@@ -1,4 +1,4 @@
-Copyright 2022 Input Output (Hong Kong) Ltd.
+Copyright 2022-2023 Input Output (Hong Kong) Ltd.
 
    Licensed under the Apache License, Version 2.0 (the "License");
    you may not use this file except in compliance with the License.