diff --git a/doc/source/admin/components.rst b/doc/source/admin/components.rst
index c11b5cb..08671c9 100644
--- a/doc/source/admin/components.rst
+++ b/doc/source/admin/components.rst
@@ -354,6 +354,13 @@
 
      variables=/etc/zuul/variables.yaml
 
+**disk_limit_per_job**
+  This integer is the maximum number of megabytes that any one job is
+  allowed to consume on disk while it is running. If a job's scratch
+  space has more than this much space consumed, it will be aborted::
+
+      disk_limit_per_job=100
+
 merger
 """"""