diff --git a/base1432.c b/base1432.c
index 020f72e..3b826d4 100644
--- a/base1432.c
+++ b/base1432.c
@@ -4,7 +4,8 @@
  * 
  * This program is free software: you can redistribute it and/or modify
  * it under the terms of the GNU General Public License as published by
- * the Free Software Foundation, version 3.
+ * the Free Software Foundation; either version 3 of the License, or
+ * (at your option) any later version.
  *
  * This program is distributed in the hope that it will be useful, but
  * WITHOUT ANY WARRANTY; without even the implied warranty of
diff --git a/base1464.c b/base1464.c
index 517fc1b..09f698b 100644
--- a/base1464.c
+++ b/base1464.c
@@ -4,7 +4,8 @@
  * 
  * This program is free software: you can redistribute it and/or modify
  * it under the terms of the GNU General Public License as published by
- * the Free Software Foundation, version 3.
+ * the Free Software Foundation; either version 3 of the License, or
+ * (at your option) any later version.
  *
  * This program is distributed in the hope that it will be useful, but
  * WITHOUT ANY WARRANTY; without even the implied warranty of
diff --git a/base16384.1 b/base16384.1
index fd1b3e4..7630b8c 100644
--- a/base16384.1
+++ b/base16384.1
@@ -73,8 +73,9 @@ This file is part of
 .IR "base16384" .
 .LP
 Base16384 is free software; you can redistribute it and/or modify it under the
-terms of the GNU General Public License Version 3 as published by the Free
-Software Foundation.
+terms of the GNU General Public License as published by the Free Software
+Foundation; either version 3 of the License, or (at your option) any later
+version.
 .LP
 Base16384 is distributed in the hope that it will be useful, but WITHOUT ANY
 WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR
diff --git a/base16384.c b/base16384.c
index 2e466de..542660e 100644
--- a/base16384.c
+++ b/base16384.c
@@ -4,7 +4,8 @@
  * 
  * This program is free software: you can redistribute it and/or modify
  * it under the terms of the GNU General Public License as published by
- * the Free Software Foundation, version 3.
+ * the Free Software Foundation; either version 3 of the License, or
+ * (at your option) any later version.
  *
  * This program is distributed in the hope that it will be useful, but
  * WITHOUT ANY WARRANTY; without even the implied warranty of
diff --git a/base16384.h b/base16384.h
index daaae49..9faa14d 100644
--- a/base16384.h
+++ b/base16384.h
@@ -7,7 +7,8 @@
  * 
  * This program is free software: you can redistribute it and/or modify
  * it under the terms of the GNU General Public License as published by
- * the Free Software Foundation, version 3.
+ * the Free Software Foundation; either version 3 of the License, or
+ * (at your option) any later version.
  *
  * This program is distributed in the hope that it will be useful, but
  * WITHOUT ANY WARRANTY; without even the implied warranty of
diff --git a/file.c b/file.c
index 3d50442..b1ed8c0 100644
--- a/file.c
+++ b/file.c
@@ -4,7 +4,8 @@
  * 
  * This program is free software: you can redistribute it and/or modify
  * it under the terms of the GNU General Public License as published by
- * the Free Software Foundation, version 3.
+ * the Free Software Foundation; either version 3 of the License, or
+ * (at your option) any later version.
  *
  * This program is distributed in the hope that it will be useful, but
  * WITHOUT ANY WARRANTY; without even the implied warranty of