diff --git a/specification/app/resource-manager/Microsoft.App/stable/2022-03-01/ContainerApps.json b/specification/app/resource-manager/Microsoft.App/stable/2022-03-01/ContainerApps.json
index a2e036007ab9..080cb2828930 100644
--- a/specification/app/resource-manager/Microsoft.App/stable/2022-03-01/ContainerApps.json
+++ b/specification/app/resource-manager/Microsoft.App/stable/2022-03-01/ContainerApps.json
@@ -655,6 +655,10 @@
         "passwordSecretRef": {
           "description": "The name of the Secret that contains the registry login password",
           "type": "string"
+        },
+        "identity": {
+          "description": "A Managed Identity to use to authenticate with Azure Container Registry. For user-assigned identities, use the full user-assigned identity Resource ID. For system-assigned identities, use 'system'",
+          "type": "string"
         }
       }
     },