diff --git a/source/reference/program/mongostat.txt b/source/reference/program/mongostat.txt
index 49ee6709486..4b2df75dd1e 100644
--- a/source/reference/program/mongostat.txt
+++ b/source/reference/program/mongostat.txt
@@ -243,6 +243,7 @@ average operations per second.
    REC        recovering
    UNK        unknown
    SLV        :term:`slave`
+   RTR        mongos process ("router")
    =========  ====================
 
 Usage