diff --git a/doc/keywords.txt b/doc/keywords.txt
index 6c8b31f..b2689d3 100644
--- a/doc/keywords.txt
+++ b/doc/keywords.txt
@@ -36,6 +36,7 @@ BOOST_PP_REPEAT_2ND
 BOOST_PP_REPEAT_3RD
 BOOST_PP_STRINGIZE
 BOOST_PP_SUB
+BOOST_PP_TUPLE_EAT
 BOOST_PP_TUPLE_ELEM
 BOOST_PP_WHILE
 BOOST_PP_XOR