diff --git a/xyz/openbmc_project/Led/Physical.interface.yaml b/xyz/openbmc_project/Led/Physical.interface.yaml
index c0ca00e..f4f9784 100644
--- a/xyz/openbmc_project/Led/Physical.interface.yaml
+++ b/xyz/openbmc_project/Led/Physical.interface.yaml
@@ -20,6 +20,12 @@
       description: >
         Color that the LED can emit.
 
+    - name: Period
+      type: uint16
+      default: 1000
+      description: >
+        LED blink period expressed as milliseconds per on/off cycle.
+
 enumerations:
     - name: Action
       description: >