diff --git a/NOTICE.md b/NOTICE.md
index 45fb5738..798704f3 100644
--- a/NOTICE.md
+++ b/NOTICE.md
@@ -1,4 +1,4 @@
-QPDF is copyright (c) 2005-2022 Jay Berkenbilt
+QPDF is copyright (c) 2005-2023 Jay Berkenbilt
 
 Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file except in compliance with the License. You may obtain a copy of the License at
 
diff --git a/README-maintainer b/README-maintainer
index 2ecbfaa6..316a9507 100644
--- a/README-maintainer
+++ b/README-maintainer
@@ -290,7 +290,7 @@ RELEASE PREPARATION
   * debian package -- search for copyright.*berkenbilt in debian/copyright
   * qtest-driver, TestDriver.pm in qtest source
 
-  Copyright last updated: 2022.
+  Copyright last updated: 2023.
 
 * Take a look at "External Libraries" in TODO to see if we need to
   make any changes. There is still some automation work left to do, so
diff --git a/README.md b/README.md
index e7b2b601..06c52d6a 100644
--- a/README.md
+++ b/README.md
@@ -15,7 +15,7 @@ The public key used to sign qpdf source distributions has fingerprint `C2C9 6B10
 
 # Copyright, License
 
-QPDF is copyright (c) 2005-2022 Jay Berkenbilt
+QPDF is copyright (c) 2005-2023 Jay Berkenbilt
 
 Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file except in compliance with the License. You may obtain a copy of the License at
 
diff --git a/appimage/build-appimage b/appimage/build-appimage
index db85375d..8cad9f1f 100755
--- a/appimage/build-appimage
+++ b/appimage/build-appimage
@@ -1,6 +1,6 @@
 #!/bin/bash
 
-# Copyright (c) 2019-2022 Jay Berkenbilt and Kurt Pfeifle
+# Copyright (c) 2019-2023 Jay Berkenbilt and Kurt Pfeifle
 #
 # This script is used to build an 'AppImage' from GitHub sources of
 # QPDF (see https://appimage.org/). It is used in CI, but it also
diff --git a/appimage/qpdf.appdata.xml b/appimage/qpdf.appdata.xml
index 3896f37c..77a24eb8 100644
--- a/appimage/qpdf.appdata.xml
+++ b/appimage/qpdf.appdata.xml
@@ -1,5 +1,5 @@
 <?xml version="1.0" encoding="UTF-8"?>
-<!-- Copyright 2005-2022 Jay Berkenbilt -->
+<!-- Copyright 2005-2023 Jay Berkenbilt -->
 <component>
 	<id>org.QPDF.qpdf.desktop</id>
 	<metadata_license>MIT</metadata_license>
diff --git a/include/qpdf/Buffer.hh b/include/qpdf/Buffer.hh
index 40d1b591..c5d55da1 100644
--- a/include/qpdf/Buffer.hh
+++ b/include/qpdf/Buffer.hh
@@ -1,4 +1,4 @@
-// Copyright (c) 2005-2022 Jay Berkenbilt
+// Copyright (c) 2005-2023 Jay Berkenbilt
 //
 // This file is part of qpdf.
 //
diff --git a/include/qpdf/BufferInputSource.hh b/include/qpdf/BufferInputSource.hh
index 1a93815b..c5a2eae5 100644
--- a/include/qpdf/BufferInputSource.hh
+++ b/include/qpdf/BufferInputSource.hh
@@ -1,4 +1,4 @@
-// Copyright (c) 2005-2022 Jay Berkenbilt
+// Copyright (c) 2005-2023 Jay Berkenbilt
 //
 // This file is part of qpdf.
 //
diff --git a/include/qpdf/ClosedFileInputSource.hh b/include/qpdf/ClosedFileInputSource.hh
index 58c78f73..467c8c03 100644
--- a/include/qpdf/ClosedFileInputSource.hh
+++ b/include/qpdf/ClosedFileInputSource.hh
@@ -1,4 +1,4 @@
-// Copyright (c) 2005-2022 Jay Berkenbilt
+// Copyright (c) 2005-2023 Jay Berkenbilt
 //
 // This file is part of qpdf.
 //
diff --git a/include/qpdf/Constants.h b/include/qpdf/Constants.h
index e3626ead..995857ab 100644
--- a/include/qpdf/Constants.h
+++ b/include/qpdf/Constants.h
@@ -1,4 +1,4 @@
-/* Copyright (c) 2005-2022 Jay Berkenbilt
+/* Copyright (c) 2005-2023 Jay Berkenbilt
  *
  * This file is part of qpdf.
  *
diff --git a/include/qpdf/DLL.h b/include/qpdf/DLL.h
index d72144f1..e3beace6 100644
--- a/include/qpdf/DLL.h
+++ b/include/qpdf/DLL.h
@@ -1,4 +1,4 @@
-/* Copyright (c) 2005-2022 Jay Berkenbilt
+/* Copyright (c) 2005-2023 Jay Berkenbilt
  *
  * This file is part of qpdf.
  *
diff --git a/include/qpdf/FileInputSource.hh b/include/qpdf/FileInputSource.hh
index 9e0d57fb..52d4a2e8 100644
--- a/include/qpdf/FileInputSource.hh
+++ b/include/qpdf/FileInputSource.hh
@@ -1,4 +1,4 @@
-// Copyright (c) 2005-2022 Jay Berkenbilt
+// Copyright (c) 2005-2023 Jay Berkenbilt
 //
 // This file is part of qpdf.
 //
diff --git a/include/qpdf/InputSource.hh b/include/qpdf/InputSource.hh
index aa79d532..68a787c6 100644
--- a/include/qpdf/InputSource.hh
+++ b/include/qpdf/InputSource.hh
@@ -1,4 +1,4 @@
-// Copyright (c) 2005-2022 Jay Berkenbilt
+// Copyright (c) 2005-2023 Jay Berkenbilt
 //
 // This file is part of qpdf.
 //
diff --git a/include/qpdf/JSON.hh b/include/qpdf/JSON.hh
index b368df99..34333e93 100644
--- a/include/qpdf/JSON.hh
+++ b/include/qpdf/JSON.hh
@@ -1,4 +1,4 @@
-// Copyright (c) 2005-2022 Jay Berkenbilt
+// Copyright (c) 2005-2023 Jay Berkenbilt
 //
 // This file is part of qpdf.
 //
diff --git a/include/qpdf/PDFVersion.hh b/include/qpdf/PDFVersion.hh
index 874e8f55..03d78899 100644
--- a/include/qpdf/PDFVersion.hh
+++ b/include/qpdf/PDFVersion.hh
@@ -1,4 +1,4 @@
-// Copyright (c) 2005-2022 Jay Berkenbilt
+// Copyright (c) 2005-2023 Jay Berkenbilt
 //
 // This file is part of qpdf.
 //
diff --git a/include/qpdf/Pipeline.hh b/include/qpdf/Pipeline.hh
index 7a0d0029..a35e7ec6 100644
--- a/include/qpdf/Pipeline.hh
+++ b/include/qpdf/Pipeline.hh
@@ -1,4 +1,4 @@
-// Copyright (c) 2005-2022 Jay Berkenbilt
+// Copyright (c) 2005-2023 Jay Berkenbilt
 //
 // This file is part of qpdf.
 //
diff --git a/include/qpdf/Pl_Buffer.hh b/include/qpdf/Pl_Buffer.hh
index 6f7bb966..e2f71094 100644
--- a/include/qpdf/Pl_Buffer.hh
+++ b/include/qpdf/Pl_Buffer.hh
@@ -1,4 +1,4 @@
-// Copyright (c) 2005-2022 Jay Berkenbilt
+// Copyright (c) 2005-2023 Jay Berkenbilt
 //
 // This file is part of qpdf.
 //
diff --git a/include/qpdf/Pl_Concatenate.hh b/include/qpdf/Pl_Concatenate.hh
index 4d6bef18..6ddb61c9 100644
--- a/include/qpdf/Pl_Concatenate.hh
+++ b/include/qpdf/Pl_Concatenate.hh
@@ -1,4 +1,4 @@
-// Copyright (c) 2005-2022 Jay Berkenbilt
+// Copyright (c) 2005-2023 Jay Berkenbilt
 //
 // This file is part of qpdf.
 //
diff --git a/include/qpdf/Pl_Count.hh b/include/qpdf/Pl_Count.hh
index 1df32ebb..2367aae9 100644
--- a/include/qpdf/Pl_Count.hh
+++ b/include/qpdf/Pl_Count.hh
@@ -1,4 +1,4 @@
-// Copyright (c) 2005-2022 Jay Berkenbilt
+// Copyright (c) 2005-2023 Jay Berkenbilt
 //
 // This file is part of qpdf.
 //
diff --git a/include/qpdf/Pl_DCT.hh b/include/qpdf/Pl_DCT.hh
index 3916204f..543967ec 100644
--- a/include/qpdf/Pl_DCT.hh
+++ b/include/qpdf/Pl_DCT.hh
@@ -1,4 +1,4 @@
-// Copyright (c) 2005-2022 Jay Berkenbilt
+// Copyright (c) 2005-2023 Jay Berkenbilt
 //
 // This file is part of qpdf.
 //
diff --git a/include/qpdf/Pl_Discard.hh b/include/qpdf/Pl_Discard.hh
index ae63b8dc..1754fcab 100644
--- a/include/qpdf/Pl_Discard.hh
+++ b/include/qpdf/Pl_Discard.hh
@@ -1,4 +1,4 @@
-// Copyright (c) 2005-2022 Jay Berkenbilt
+// Copyright (c) 2005-2023 Jay Berkenbilt
 //
 // This file is part of qpdf.
 //
diff --git a/include/qpdf/Pl_Flate.hh b/include/qpdf/Pl_Flate.hh
index ee797180..c31d4a0b 100644
--- a/include/qpdf/Pl_Flate.hh
+++ b/include/qpdf/Pl_Flate.hh
@@ -1,4 +1,4 @@
-// Copyright (c) 2005-2022 Jay Berkenbilt
+// Copyright (c) 2005-2023 Jay Berkenbilt
 //
 // This file is part of qpdf.
 //
diff --git a/include/qpdf/Pl_Function.hh b/include/qpdf/Pl_Function.hh
index 41c56a98..7df164d1 100644
--- a/include/qpdf/Pl_Function.hh
+++ b/include/qpdf/Pl_Function.hh
@@ -1,4 +1,4 @@
-// Copyright (c) 2005-2022 Jay Berkenbilt
+// Copyright (c) 2005-2023 Jay Berkenbilt
 //
 // This file is part of qpdf.
 //
diff --git a/include/qpdf/Pl_OStream.hh b/include/qpdf/Pl_OStream.hh
index 01cede8b..7bb3410d 100644
--- a/include/qpdf/Pl_OStream.hh
+++ b/include/qpdf/Pl_OStream.hh
@@ -1,4 +1,4 @@
-// Copyright (c) 2005-2022 Jay Berkenbilt
+// Copyright (c) 2005-2023 Jay Berkenbilt
 //
 // This file is part of qpdf.
 //
diff --git a/include/qpdf/Pl_QPDFTokenizer.hh b/include/qpdf/Pl_QPDFTokenizer.hh
index 12a69b49..ce3615ec 100644
--- a/include/qpdf/Pl_QPDFTokenizer.hh
+++ b/include/qpdf/Pl_QPDFTokenizer.hh
@@ -1,4 +1,4 @@
-// Copyright (c) 2005-2022 Jay Berkenbilt
+// Copyright (c) 2005-2023 Jay Berkenbilt
 //
 // This file is part of qpdf.
 //
diff --git a/include/qpdf/Pl_RunLength.hh b/include/qpdf/Pl_RunLength.hh
index 92023f40..94f9ef57 100644
--- a/include/qpdf/Pl_RunLength.hh
+++ b/include/qpdf/Pl_RunLength.hh
@@ -1,4 +1,4 @@
-// Copyright (c) 2005-2022 Jay Berkenbilt
+// Copyright (c) 2005-2023 Jay Berkenbilt
 //
 // This file is part of qpdf.
 //
diff --git a/include/qpdf/Pl_StdioFile.hh b/include/qpdf/Pl_StdioFile.hh
index ae3a86e9..1508af2b 100644
--- a/include/qpdf/Pl_StdioFile.hh
+++ b/include/qpdf/Pl_StdioFile.hh
@@ -1,4 +1,4 @@
-// Copyright (c) 2005-2022 Jay Berkenbilt
+// Copyright (c) 2005-2023 Jay Berkenbilt
 //
 // This file is part of qpdf.
 //
diff --git a/include/qpdf/Pl_String.hh b/include/qpdf/Pl_String.hh
index 906a2660..cd4ec0f4 100644
--- a/include/qpdf/Pl_String.hh
+++ b/include/qpdf/Pl_String.hh
@@ -1,4 +1,4 @@
-// Copyright (c) 2005-2022 Jay Berkenbilt
+// Copyright (c) 2005-2023 Jay Berkenbilt
 //
 // This file is part of qpdf.
 //
diff --git a/include/qpdf/PointerHolder.hh b/include/qpdf/PointerHolder.hh
index 04ff2de9..476abac2 100644
--- a/include/qpdf/PointerHolder.hh
+++ b/include/qpdf/PointerHolder.hh
@@ -1,4 +1,4 @@
-// Copyright (c) 2005-2022 Jay Berkenbilt
+// Copyright (c) 2005-2023 Jay Berkenbilt
 //
 // This file is part of qpdf.
 //
diff --git a/include/qpdf/QIntC.hh b/include/qpdf/QIntC.hh
index b896a026..4f224560 100644
--- a/include/qpdf/QIntC.hh
+++ b/include/qpdf/QIntC.hh
@@ -1,4 +1,4 @@
-// Copyright (c) 2005-2022 Jay Berkenbilt
+// Copyright (c) 2005-2023 Jay Berkenbilt
 //
 // This file is part of qpdf.
 //
diff --git a/include/qpdf/QPDF.hh b/include/qpdf/QPDF.hh
index 3f998b9c..5cc7a2f2 100644
--- a/include/qpdf/QPDF.hh
+++ b/include/qpdf/QPDF.hh
@@ -1,4 +1,4 @@
-// Copyright (c) 2005-2022 Jay Berkenbilt
+// Copyright (c) 2005-2023 Jay Berkenbilt
 //
 // This file is part of qpdf.
 //
diff --git a/include/qpdf/QPDFAcroFormDocumentHelper.hh b/include/qpdf/QPDFAcroFormDocumentHelper.hh
index 3c4f1ca3..4539b52d 100644
--- a/include/qpdf/QPDFAcroFormDocumentHelper.hh
+++ b/include/qpdf/QPDFAcroFormDocumentHelper.hh
@@ -1,4 +1,4 @@
-// Copyright (c) 2005-2022 Jay Berkenbilt
+// Copyright (c) 2005-2023 Jay Berkenbilt
 //
 // This file is part of qpdf.
 //
diff --git a/include/qpdf/QPDFAnnotationObjectHelper.hh b/include/qpdf/QPDFAnnotationObjectHelper.hh
index 2f0bc6b9..a28bf495 100644
--- a/include/qpdf/QPDFAnnotationObjectHelper.hh
+++ b/include/qpdf/QPDFAnnotationObjectHelper.hh
@@ -1,4 +1,4 @@
-// Copyright (c) 2005-2022 Jay Berkenbilt
+// Copyright (c) 2005-2023 Jay Berkenbilt
 //
 // This file is part of qpdf.
 //
diff --git a/include/qpdf/QPDFCryptoImpl.hh b/include/qpdf/QPDFCryptoImpl.hh
index a88b416a..5345b45b 100644
--- a/include/qpdf/QPDFCryptoImpl.hh
+++ b/include/qpdf/QPDFCryptoImpl.hh
@@ -1,4 +1,4 @@
-// Copyright (c) 2005-2022 Jay Berkenbilt
+// Copyright (c) 2005-2023 Jay Berkenbilt
 //
 // This file is part of qpdf.
 //
diff --git a/include/qpdf/QPDFCryptoProvider.hh b/include/qpdf/QPDFCryptoProvider.hh
index d8577859..122cb882 100644
--- a/include/qpdf/QPDFCryptoProvider.hh
+++ b/include/qpdf/QPDFCryptoProvider.hh
@@ -1,4 +1,4 @@
-// Copyright (c) 2005-2022 Jay Berkenbilt
+// Copyright (c) 2005-2023 Jay Berkenbilt
 //
 // This file is part of qpdf.
 //
diff --git a/include/qpdf/QPDFDocumentHelper.hh b/include/qpdf/QPDFDocumentHelper.hh
index e78788ab..dcdecf01 100644
--- a/include/qpdf/QPDFDocumentHelper.hh
+++ b/include/qpdf/QPDFDocumentHelper.hh
@@ -1,4 +1,4 @@
-// Copyright (c) 2005-2022 Jay Berkenbilt
+// Copyright (c) 2005-2023 Jay Berkenbilt
 //
 // This file is part of qpdf.
 //
diff --git a/include/qpdf/QPDFEFStreamObjectHelper.hh b/include/qpdf/QPDFEFStreamObjectHelper.hh
index 7c943453..2a24c0c3 100644
--- a/include/qpdf/QPDFEFStreamObjectHelper.hh
+++ b/include/qpdf/QPDFEFStreamObjectHelper.hh
@@ -1,4 +1,4 @@
-// Copyright (c) 2005-2022 Jay Berkenbilt
+// Copyright (c) 2005-2023 Jay Berkenbilt
 //
 // This file is part of qpdf.
 //
diff --git a/include/qpdf/QPDFEmbeddedFileDocumentHelper.hh b/include/qpdf/QPDFEmbeddedFileDocumentHelper.hh
index 0243be4e..9bab725a 100644
--- a/include/qpdf/QPDFEmbeddedFileDocumentHelper.hh
+++ b/include/qpdf/QPDFEmbeddedFileDocumentHelper.hh
@@ -1,4 +1,4 @@
-// Copyright (c) 2005-2022 Jay Berkenbilt
+// Copyright (c) 2005-2023 Jay Berkenbilt
 //
 // This file is part of qpdf.
 //
diff --git a/include/qpdf/QPDFExc.hh b/include/qpdf/QPDFExc.hh
index c596e072..b53aa405 100644
--- a/include/qpdf/QPDFExc.hh
+++ b/include/qpdf/QPDFExc.hh
@@ -1,4 +1,4 @@
-// Copyright (c) 2005-2022 Jay Berkenbilt
+// Copyright (c) 2005-2023 Jay Berkenbilt
 //
 // This file is part of qpdf.
 //
diff --git a/include/qpdf/QPDFFileSpecObjectHelper.hh b/include/qpdf/QPDFFileSpecObjectHelper.hh
index 30f4eed9..fa70c035 100644
--- a/include/qpdf/QPDFFileSpecObjectHelper.hh
+++ b/include/qpdf/QPDFFileSpecObjectHelper.hh
@@ -1,4 +1,4 @@
-// Copyright (c) 2005-2022 Jay Berkenbilt
+// Copyright (c) 2005-2023 Jay Berkenbilt
 //
 // This file is part of qpdf.
 //
diff --git a/include/qpdf/QPDFFormFieldObjectHelper.hh b/include/qpdf/QPDFFormFieldObjectHelper.hh
index 4bad5d1e..1d8317b3 100644
--- a/include/qpdf/QPDFFormFieldObjectHelper.hh
+++ b/include/qpdf/QPDFFormFieldObjectHelper.hh
@@ -1,4 +1,4 @@
-// Copyright (c) 2005-2022 Jay Berkenbilt
+// Copyright (c) 2005-2023 Jay Berkenbilt
 //
 // This file is part of qpdf.
 //
diff --git a/include/qpdf/QPDFJob.hh b/include/qpdf/QPDFJob.hh
index 3e2a73a0..3b6a3a27 100644
--- a/include/qpdf/QPDFJob.hh
+++ b/include/qpdf/QPDFJob.hh
@@ -1,4 +1,4 @@
-// Copyright (c) 2005-2022 Jay Berkenbilt
+// Copyright (c) 2005-2023 Jay Berkenbilt
 //
 // This file is part of qpdf.
 //
diff --git a/include/qpdf/QPDFLogger.hh b/include/qpdf/QPDFLogger.hh
index 54d91d60..6875721f 100644
--- a/include/qpdf/QPDFLogger.hh
+++ b/include/qpdf/QPDFLogger.hh
@@ -1,4 +1,4 @@
-// Copyright (c) 2005-2022 Jay Berkenbilt
+// Copyright (c) 2005-2023 Jay Berkenbilt
 //
 // This file is part of qpdf.
 //
diff --git a/include/qpdf/QPDFMatrix.hh b/include/qpdf/QPDFMatrix.hh
index 3dc26a7c..0756921a 100644
--- a/include/qpdf/QPDFMatrix.hh
+++ b/include/qpdf/QPDFMatrix.hh
@@ -1,4 +1,4 @@
-// Copyright (c) 2005-2022 Jay Berkenbilt
+// Copyright (c) 2005-2023 Jay Berkenbilt
 //
 // This file is part of qpdf.
 //
diff --git a/include/qpdf/QPDFNameTreeObjectHelper.hh b/include/qpdf/QPDFNameTreeObjectHelper.hh
index 006ab158..8dbe4191 100644
--- a/include/qpdf/QPDFNameTreeObjectHelper.hh
+++ b/include/qpdf/QPDFNameTreeObjectHelper.hh
@@ -1,4 +1,4 @@
-// Copyright (c) 2005-2022 Jay Berkenbilt
+// Copyright (c) 2005-2023 Jay Berkenbilt
 //
 // This file is part of qpdf.
 //
diff --git a/include/qpdf/QPDFNumberTreeObjectHelper.hh b/include/qpdf/QPDFNumberTreeObjectHelper.hh
index c1ffc251..f88f185a 100644
--- a/include/qpdf/QPDFNumberTreeObjectHelper.hh
+++ b/include/qpdf/QPDFNumberTreeObjectHelper.hh
@@ -1,4 +1,4 @@
-// Copyright (c) 2005-2022 Jay Berkenbilt
+// Copyright (c) 2005-2023 Jay Berkenbilt
 //
 // This file is part of qpdf.
 //
diff --git a/include/qpdf/QPDFObjGen.hh b/include/qpdf/QPDFObjGen.hh
index df9ef737..ccab4ba2 100644
--- a/include/qpdf/QPDFObjGen.hh
+++ b/include/qpdf/QPDFObjGen.hh
@@ -1,4 +1,4 @@
-// Copyright (c) 2005-2022 Jay Berkenbilt
+// Copyright (c) 2005-2023 Jay Berkenbilt
 //
 // This file is part of qpdf.
 //
diff --git a/include/qpdf/QPDFObject.hh b/include/qpdf/QPDFObject.hh
index b46b2820..85ac110e 100644
--- a/include/qpdf/QPDFObject.hh
+++ b/include/qpdf/QPDFObject.hh
@@ -1,4 +1,4 @@
-// Copyright (c) 2005-2022 Jay Berkenbilt
+// Copyright (c) 2005-2023 Jay Berkenbilt
 //
 // This file is part of qpdf.
 //
diff --git a/include/qpdf/QPDFObjectHandle.hh b/include/qpdf/QPDFObjectHandle.hh
index ae1a465b..a0a91a3d 100644
--- a/include/qpdf/QPDFObjectHandle.hh
+++ b/include/qpdf/QPDFObjectHandle.hh
@@ -1,4 +1,4 @@
-// Copyright (c) 2005-2022 Jay Berkenbilt
+// Copyright (c) 2005-2023 Jay Berkenbilt
 //
 // This file is part of qpdf.
 //
diff --git a/include/qpdf/QPDFObjectHelper.hh b/include/qpdf/QPDFObjectHelper.hh
index 7f0f21ca..e79eff9d 100644
--- a/include/qpdf/QPDFObjectHelper.hh
+++ b/include/qpdf/QPDFObjectHelper.hh
@@ -1,4 +1,4 @@
-// Copyright (c) 2005-2022 Jay Berkenbilt
+// Copyright (c) 2005-2023 Jay Berkenbilt
 //
 // This file is part of qpdf.
 //
diff --git a/include/qpdf/QPDFOutlineDocumentHelper.hh b/include/qpdf/QPDFOutlineDocumentHelper.hh
index bbbc2a63..cd11884d 100644
--- a/include/qpdf/QPDFOutlineDocumentHelper.hh
+++ b/include/qpdf/QPDFOutlineDocumentHelper.hh
@@ -1,4 +1,4 @@
-// Copyright (c) 2005-2022 Jay Berkenbilt
+// Copyright (c) 2005-2023 Jay Berkenbilt
 //
 // This file is part of qpdf.
 //
diff --git a/include/qpdf/QPDFOutlineObjectHelper.hh b/include/qpdf/QPDFOutlineObjectHelper.hh
index 11010a9b..c8b82a80 100644
--- a/include/qpdf/QPDFOutlineObjectHelper.hh
+++ b/include/qpdf/QPDFOutlineObjectHelper.hh
@@ -1,4 +1,4 @@
-// Copyright (c) 2005-2022 Jay Berkenbilt
+// Copyright (c) 2005-2023 Jay Berkenbilt
 //
 // This file is part of qpdf.
 //
diff --git a/include/qpdf/QPDFPageDocumentHelper.hh b/include/qpdf/QPDFPageDocumentHelper.hh
index f8b2ac7e..b41110fd 100644
--- a/include/qpdf/QPDFPageDocumentHelper.hh
+++ b/include/qpdf/QPDFPageDocumentHelper.hh
@@ -1,4 +1,4 @@
-// Copyright (c) 2005-2022 Jay Berkenbilt
+// Copyright (c) 2005-2023 Jay Berkenbilt
 //
 // This file is part of qpdf.
 //
diff --git a/include/qpdf/QPDFPageLabelDocumentHelper.hh b/include/qpdf/QPDFPageLabelDocumentHelper.hh
index 76aade9c..dbb0a07e 100644
--- a/include/qpdf/QPDFPageLabelDocumentHelper.hh
+++ b/include/qpdf/QPDFPageLabelDocumentHelper.hh
@@ -1,4 +1,4 @@
-// Copyright (c) 2005-2022 Jay Berkenbilt
+// Copyright (c) 2005-2023 Jay Berkenbilt
 //
 // This file is part of qpdf.
 //
diff --git a/include/qpdf/QPDFPageObjectHelper.hh b/include/qpdf/QPDFPageObjectHelper.hh
index ef3c09ca..ebb9e87e 100644
--- a/include/qpdf/QPDFPageObjectHelper.hh
+++ b/include/qpdf/QPDFPageObjectHelper.hh
@@ -1,4 +1,4 @@
-// Copyright (c) 2005-2022 Jay Berkenbilt
+// Copyright (c) 2005-2023 Jay Berkenbilt
 //
 // This file is part of qpdf.
 //
diff --git a/include/qpdf/QPDFStreamFilter.hh b/include/qpdf/QPDFStreamFilter.hh
index a9daf028..fec12851 100644
--- a/include/qpdf/QPDFStreamFilter.hh
+++ b/include/qpdf/QPDFStreamFilter.hh
@@ -1,4 +1,4 @@
-// Copyright (c) 2005-2022 Jay Berkenbilt
+// Copyright (c) 2005-2023 Jay Berkenbilt
 //
 // This file is part of qpdf.
 //
diff --git a/include/qpdf/QPDFSystemError.hh b/include/qpdf/QPDFSystemError.hh
index 22fb3fc1..6d23fa94 100644
--- a/include/qpdf/QPDFSystemError.hh
+++ b/include/qpdf/QPDFSystemError.hh
@@ -1,4 +1,4 @@
-// Copyright (c) 2005-2022 Jay Berkenbilt
+// Copyright (c) 2005-2023 Jay Berkenbilt
 //
 // This file is part of qpdf.
 //
diff --git a/include/qpdf/QPDFTokenizer.hh b/include/qpdf/QPDFTokenizer.hh
index b9642fc3..79d0d3cd 100644
--- a/include/qpdf/QPDFTokenizer.hh
+++ b/include/qpdf/QPDFTokenizer.hh
@@ -1,4 +1,4 @@
-// Copyright (c) 2005-2022 Jay Berkenbilt
+// Copyright (c) 2005-2023 Jay Berkenbilt
 //
 // This file is part of qpdf.
 //
diff --git a/include/qpdf/QPDFUsage.hh b/include/qpdf/QPDFUsage.hh
index eacfd97b..e1cadc10 100644
--- a/include/qpdf/QPDFUsage.hh
+++ b/include/qpdf/QPDFUsage.hh
@@ -1,4 +1,4 @@
-// Copyright (c) 2005-2022 Jay Berkenbilt
+// Copyright (c) 2005-2023 Jay Berkenbilt
 //
 // This file is part of qpdf.
 //
diff --git a/include/qpdf/QPDFWriter.hh b/include/qpdf/QPDFWriter.hh
index 8faf9c32..464e20a0 100644
--- a/include/qpdf/QPDFWriter.hh
+++ b/include/qpdf/QPDFWriter.hh
@@ -1,4 +1,4 @@
-// Copyright (c) 2005-2022 Jay Berkenbilt
+// Copyright (c) 2005-2023 Jay Berkenbilt
 //
 // This file is part of qpdf.
 //
diff --git a/include/qpdf/QPDFXRefEntry.hh b/include/qpdf/QPDFXRefEntry.hh
index cb816a6e..afdca768 100644
--- a/include/qpdf/QPDFXRefEntry.hh
+++ b/include/qpdf/QPDFXRefEntry.hh
@@ -1,4 +1,4 @@
-// Copyright (c) 2005-2022 Jay Berkenbilt
+// Copyright (c) 2005-2023 Jay Berkenbilt
 //
 // This file is part of qpdf.
 //
diff --git a/include/qpdf/QTC.hh b/include/qpdf/QTC.hh
index 70115981..46d65607 100644
--- a/include/qpdf/QTC.hh
+++ b/include/qpdf/QTC.hh
@@ -1,4 +1,4 @@
-// Copyright (c) 2005-2022 Jay Berkenbilt
+// Copyright (c) 2005-2023 Jay Berkenbilt
 //
 // This file is part of qpdf.
 //
diff --git a/include/qpdf/QUtil.hh b/include/qpdf/QUtil.hh
index dd452026..c2ad8448 100644
--- a/include/qpdf/QUtil.hh
+++ b/include/qpdf/QUtil.hh
@@ -1,4 +1,4 @@
-// Copyright (c) 2005-2022 Jay Berkenbilt
+// Copyright (c) 2005-2023 Jay Berkenbilt
 //
 // This file is part of qpdf.
 //
diff --git a/include/qpdf/RandomDataProvider.hh b/include/qpdf/RandomDataProvider.hh
index 023bf995..5023b4d0 100644
--- a/include/qpdf/RandomDataProvider.hh
+++ b/include/qpdf/RandomDataProvider.hh
@@ -1,4 +1,4 @@
-// Copyright (c) 2005-2022 Jay Berkenbilt
+// Copyright (c) 2005-2023 Jay Berkenbilt
 //
 // This file is part of qpdf.
 //
diff --git a/include/qpdf/Types.h b/include/qpdf/Types.h
index faf39248..fd994fb3 100644
--- a/include/qpdf/Types.h
+++ b/include/qpdf/Types.h
@@ -1,4 +1,4 @@
-/* Copyright (c) 2005-2022 Jay Berkenbilt
+/* Copyright (c) 2005-2023 Jay Berkenbilt
  *
  * This file is part of qpdf.
  *
diff --git a/include/qpdf/qpdf-c.h b/include/qpdf/qpdf-c.h
index 8d1b0e2f..3b56c427 100644
--- a/include/qpdf/qpdf-c.h
+++ b/include/qpdf/qpdf-c.h
@@ -1,4 +1,4 @@
-/* Copyright (c) 2005-2022 Jay Berkenbilt
+/* Copyright (c) 2005-2023 Jay Berkenbilt
  *
  * This file is part of qpdf.
  *
diff --git a/include/qpdf/qpdfjob-c.h b/include/qpdf/qpdfjob-c.h
index a1540d84..8408f0d6 100644
--- a/include/qpdf/qpdfjob-c.h
+++ b/include/qpdf/qpdfjob-c.h
@@ -1,4 +1,4 @@
-/* Copyright (c) 2005-2022 Jay Berkenbilt
+/* Copyright (c) 2005-2023 Jay Berkenbilt
  *
  * This file is part of qpdf.
  *
diff --git a/include/qpdf/qpdflogger-c.h b/include/qpdf/qpdflogger-c.h
index 235efac1..96276c07 100644
--- a/include/qpdf/qpdflogger-c.h
+++ b/include/qpdf/qpdflogger-c.h
@@ -1,4 +1,4 @@
-/* Copyright (c) 2005-2022 Jay Berkenbilt
+/* Copyright (c) 2005-2023 Jay Berkenbilt
  *
  * This file is part of qpdf.
  *
diff --git a/libqpdf/QPDFJob_argv.cc b/libqpdf/QPDFJob_argv.cc
index 89d6b106..55696f5d 100644
--- a/libqpdf/QPDFJob_argv.cc
+++ b/libqpdf/QPDFJob_argv.cc
@@ -122,7 +122,7 @@ ArgParser::argCopyright()
         << this->ap.getProgname()
         << " version " << QPDF::QPDFVersion() << "\n"
         << "\n"
-        << "Copyright (c) 2005-2022 Jay Berkenbilt\n"
+        << "Copyright (c) 2005-2023 Jay Berkenbilt\n"
         << "QPDF is licensed under the Apache License, Version 2.0 (the \"License\");\n"
         << "you may not use this file except in compliance with the License.\n"
         << "You may obtain a copy of the License at\n"
diff --git a/manual/conf.py b/manual/conf.py
index 8228b259..0f69dd90 100644
--- a/manual/conf.py
+++ b/manual/conf.py
@@ -13,7 +13,7 @@ import sys
 sys.path.append(os.path.abspath("./_ext"))
 
 project = 'QPDF'
-copyright = '2005-2022, Jay Berkenbilt'
+copyright = '2005-2023, Jay Berkenbilt'
 author = 'Jay Berkenbilt'
 # make_dist and the CI build lexically find the release version from this file.
 release = '11.3.0'
diff --git a/qtest/bin/qtest-driver b/qtest/bin/qtest-driver
index fa8d82c3..0bef9681 100755
--- a/qtest/bin/qtest-driver
+++ b/qtest/bin/qtest-driver
@@ -2,7 +2,7 @@
 #
 # This file is part of qtest.
 #
-# Copyright 1993-2022, Jay Berkenbilt
+# Copyright 1993-2023, Jay Berkenbilt
 #
 # QTest is distributed under the terms of version 2.0 of the Artistic
 # license which may be found in the source distribution.
diff --git a/qtest/module/TestDriver.pm b/qtest/module/TestDriver.pm
index 28e8552c..a6a5e1c4 100644
--- a/qtest/module/TestDriver.pm
+++ b/qtest/module/TestDriver.pm
@@ -2,7 +2,7 @@
 #
 # This file is part of qtest.
 #
-# Copyright 1993-2022, Jay Berkenbilt
+# Copyright 1993-2023, Jay Berkenbilt
 #
 # QTest is distributed under the terms of version 2.0 of the Artistic
 # license which may be found in the source distribution.