diff --git a/doc/jemalloc.xml.in b/doc/jemalloc.xml.in
index 058e9db9..a73f0ad7 100644
--- a/doc/jemalloc.xml.in
+++ b/doc/jemalloc.xml.in
@@ -944,6 +944,9 @@ mallctl("arena." STRINGIFY(MALLCTL_ARENAS_ALL) ".decay",
         <citerefentry><refentrytitle>munmap</refentrytitle>
         <manvolnum>2</manvolnum></citerefentry> or equivalent (see <link
         linkend="stats.retained">stats.retained</link> for related details).
+        It also makes jemalloc use <citerefentry>
+        <refentrytitle>mmap</refentrytitle><manvolnum>2</manvolnum>
+        </citerefentry> in a more greedy way, mapping larger chunks in one go.
         This option is disabled by default unless discarding virtual memory is
         known to trigger
         platform-specific performance problems, e.g. for [64-bit] Linux, which