diff --git a/specification/storage/data-plane/Microsoft.BlobStorage/preview/2019-12-12/blob.json b/specification/storage/data-plane/Microsoft.BlobStorage/preview/2019-12-12/blob.json
index 61ad064b8f06..4ed0358e2c7d 100644
--- a/specification/storage/data-plane/Microsoft.BlobStorage/preview/2019-12-12/blob.json
+++ b/specification/storage/data-plane/Microsoft.BlobStorage/preview/2019-12-12/blob.json
@@ -2949,6 +2949,11 @@
                 "type": "string",
                 "description": "Indicates the version of the Blob service used to execute the request. This header is returned for requests made against version 2009-09-19 and above."
               },
+              "x-ms-version-id": {
+                "x-ms-client-name": "VersionId",
+                "type": "string",
+                "description": "A DateTime value returned by the service that uniquely identifies the blob. The value of this header indicates the blob version, and may be used in subsequent requests to access this version of the blob."
+              },
               "Accept-Ranges": {
                 "type": "string",
                 "description": "Indicates that the service supports requests for partial blob content."