diff --git a/docs/monasca-api-spec.md b/docs/monasca-api-spec.md
index 02730c2f3..5f7d8da84 100644
--- a/docs/monasca-api-spec.md
+++ b/docs/monasca-api-spec.md
@@ -1679,7 +1679,7 @@ Cache-Control: no-cache
 {  
    "name":"Average CPU percent greater than 10",
    "description":"The average CPU percent is greater than 10",
-   "expression":"(avg(cpu,user_perc{hostname=devstack}) > 10)",
+   "expression":"(avg(cpu.user_perc{hostname=devstack}) > 10)",
    "match_by":[
      "hostname"
    ],