diff --git a/doc/tesseract.1.asc b/doc/tesseract.1.asc
index 67ec08d41f..f81db7d6a2 100644
--- a/doc/tesseract.1.asc
+++ b/doc/tesseract.1.asc
@@ -116,6 +116,9 @@ SINGLE OPTIONS
 '-h, --help'::
 	Show help message.
 
+'--help-extra'::
+	Show extra help for advanced users.
+
 '--help-psm'::
 	Show page segmentation modes.