diff --git a/man2rst.py b/man2rst.py
index 90e5f850..ae7c79bd 100755
--- a/man2rst.py
+++ b/man2rst.py
@@ -8,6 +8,9 @@ def man2rst(f):
     expect_arg = False
     in_arg = False
 
+    sys.stdout.write('.. DO NOT MODIFY THIS FILE!  '
+                     'It was generated by man2rst.py\n\n')
+
     for line in f:
         line = line.rstrip()