diff --git a/xyz/openbmc_project/Logging/Entry.interface.yaml b/xyz/openbmc_project/Logging/Entry.interface.yaml
index 5e6cf2e..0f1953e 100755
--- a/xyz/openbmc_project/Logging/Entry.interface.yaml
+++ b/xyz/openbmc_project/Logging/Entry.interface.yaml
@@ -33,6 +33,14 @@
           this error log has been resolved. This will start out 'false' by
           default. Setting this to 'true' will NOT result in the error log being
           deleted.
+    - name: UpdateTimestamp
+      type: uint64
+      description: >
+          The timestamp when any property was last modified, in milliseconds
+          since the epoch (1 Jan 1970 00:00:00 UTC).  As only the
+          Resolved property has a reason to change, a value that doesn't
+          match the Timestamp property's value (which indicates when the
+          log was created) would indicate that Resolved was changed.
 
 enumerations:
     - name: Level