diff --git a/units/tmp.mount b/units/tmp.mount
index 7367f7e642..0b0d6ae56d 100644
--- a/units/tmp.mount
+++ b/units/tmp.mount
@@ -7,6 +7,7 @@
 
 [Unit]
 Description=Temporary Directory
+Documentation=man:hier(7)
 Before=local-fs.target
 
 [Mount]