diff --git a/Documentation/driver-api/index.rst b/Documentation/driver-api/index.rst
index 6567187e7687..3eb0085d5e42 100644
--- a/Documentation/driver-api/index.rst
+++ b/Documentation/driver-api/index.rst
@@ -48,6 +48,7 @@ available subsections can be seen below.
    scsi
    libata
    target
+   mailbox
    mtdnand
    miscellaneous
    mei/index
diff --git a/Documentation/mailbox.txt b/Documentation/driver-api/mailbox.rst
similarity index 100%
rename from Documentation/mailbox.txt
rename to Documentation/driver-api/mailbox.rst