diff --git a/README.md b/README.md
index 841bc61..081eef1 100644
--- a/README.md
+++ b/README.md
@@ -55,6 +55,7 @@ If using a default value, the key is optional and does not need to be defined
 - Any valid Condition ID value (Default is -1)
 #### duration
 - Any float value (Default is 0.0)
+- Set to -1 for infinite duration
 
 ## Example
 ```js