diff --git a/docs/admin-api.openapi.json b/docs/admin-api.openapi.json
index 80c9d03..f4a04d9 100644
--- a/docs/admin-api.openapi.json
+++ b/docs/admin-api.openapi.json
@@ -6485,6 +6485,10 @@
           "percent": {
             "type": "integer",
             "description": "Percent is absent rather than zero when the total is unknown: an invented percentage that stops moving is worse than a byte count that keeps rising."
+          },
+          "phase": {
+            "type": "string",
+            "description": "Phase is empty while the bytes arrive, \"checking\" while a set's files are checked against the mirror's checksums."
           }
         }
       },