diff --git a/syntax/autoconf.nanorc b/syntax/autoconf.nanorc
index 49b7d92b..918cfb9d 100644
--- a/syntax/autoconf.nanorc
+++ b/syntax/autoconf.nanorc
@@ -1,5 +1,8 @@
 ## Syntax highlighting for Autoconf.
 
+## Original author:  Benno Schulenberg
+## License:  GPL version 3 or newer
+
 syntax autoconf "\.(ac|m4)$"
 comment "#"
 
diff --git a/syntax/changelog.nanorc b/syntax/changelog.nanorc
index 003b37f6..46272380 100644
--- a/syntax/changelog.nanorc
+++ b/syntax/changelog.nanorc
@@ -1,5 +1,8 @@
 ## Syntax highlighting for Changelogs.
 
+## Original author:  Benno Schulenberg
+## License:  GPL version 3 or newer
+
 syntax changelog "Change[Ll]og[^/]*$"
 
 # Author lines.
diff --git a/syntax/po.nanorc b/syntax/po.nanorc
index 33dda351..42b703f7 100644
--- a/syntax/po.nanorc
+++ b/syntax/po.nanorc
@@ -1,5 +1,8 @@
 ## Syntax highlighting for PO files.
 
+## Original author:  Benno Schulenberg
+## License:  GPL version 3 or newer
+
 syntax po "\.pot?$"
 comment "#"
 
diff --git a/syntax/texinfo.nanorc b/syntax/texinfo.nanorc
index e0080b96..5fdc1cad 100644
--- a/syntax/texinfo.nanorc
+++ b/syntax/texinfo.nanorc
@@ -1,5 +1,8 @@
 ## Syntax highlighting for Texinfo files.
 
+## Original author:  Benno Schulenberg
+## License:  GPL version 3 or newer
+
 syntax texinfo "\.texi$"
 header "^\\input texinfo"
 magic "Texinfo source"