diff --git a/cloud/docker/docker.py b/cloud/docker/docker.py
index 59814c30e01..96254a10654 100644
--- a/cloud/docker/docker.py
+++ b/cloud/docker/docker.py
@@ -195,6 +195,7 @@ options:
         disabled, fail unless the process exits cleanly.
     default: true
   signal:
+    version_added: "2.0"
     description:
       - With the state "killed", you can alter the signal sent to the
         container.