diff --git a/bin/pygments-lexers b/bin/pygments-lexers
index c31a0418..57f593db 100755
--- a/bin/pygments-lexers
+++ b/bin/pygments-lexers
@@ -4,6 +4,7 @@ from pygments import __version__
 from pygments.lexers import get_all_lexers
 
 print "# AUTOMATICALLY GENERATED BY bin/pygments-lexers"
+print "# DO NOT MODIFIY. YOUR PULL WILL BE REJECTED."
 print "# Pygments version %s" % __version__
 print "---"
 
diff --git a/lib/linguist/lexers.yml b/lib/linguist/lexers.yml
index 05f245ed..51afcd79 100644
--- a/lib/linguist/lexers.yml
+++ b/lib/linguist/lexers.yml
@@ -1,4 +1,5 @@
 # AUTOMATICALLY GENERATED BY bin/pygments-lexers
+# DO NOT MODIFIY. YOUR PULL WILL BE REJECTED.
 # Pygments version 1.4
 ---
 JavaScript+Mako: