diff --git a/lib/allmodules.pl b/lib/allmodules.pl
index 82e9ec0..71dd74a 100644
--- a/lib/allmodules.pl
+++ b/lib/allmodules.pl
@@ -119,6 +119,7 @@
 
     my $content = <<"    XML";
 <?xml version="1.0" encoding="UTF-8"?>
+<!-- GENERATED FROM XML: DO NOT EDIT -->
 
 <modulefilelist>
   @{[ join "\n  " => map qq{<modulefile>$_</modulefile>} => @modules ]}
@@ -173,6 +174,7 @@
 sample file:
 
 <?xml version="1.0" encoding="UTF-8"?>
+<!-- GENERATED FROM XML: DO NOT EDIT -->
 
 <modulefilelist>
     <modulefile>core.xml</modulefile>
diff --git a/lib/metafile.pl b/lib/metafile.pl
index 081cd0f..bd6a00c 100644
--- a/lib/metafile.pl
+++ b/lib/metafile.pl
@@ -97,6 +97,7 @@
     # create resulting file contents
     my $content = <<"    XML";
 <?xml version="1.0" encoding="UTF-8" ?>
+<!-- GENERATED FROM XML: DO NOT EDIT -->
 
 <metafile>
   <basename>$basename</basename>
@@ -271,6 +272,7 @@
 sample file:
 
 <?xml version="1.0" encoding="UTF-8" ?>
+<!-- GENERATED FROM XML: DO NOT EDIT -->
 
 <metafile>
   <basename>quickreference</basename>