diff --git a/plugins/inputs/openstack/README.md b/plugins/inputs/openstack/README.md
index 98861b4580c2f..930662e9d049e 100644
--- a/plugins/inputs/openstack/README.md
+++ b/plugins/inputs/openstack/README.md
@@ -37,7 +37,7 @@ your requirements. This will help with load and cardinality as well.
 
 ```toml
 [[inputs.openstack]]
-  interval = 5m
+  interval = "5m"
   ....
   authentication_endpoint = "https://my.openstack.cloud:5000"
   ...
@@ -45,7 +45,7 @@ your requirements. This will help with load and cardinality as well.
   ....
 
 [[inputs.openstack]]
-  interval = 30m
+  interval = "30m"
   ....
   authentication_endpoint = "https://my.openstack.cloud:5000"
   ...