diff --git a/object/service.proto b/object/service.proto
index dfb4dea7..964c5ccb 100644
--- a/object/service.proto
+++ b/object/service.proto
@@ -291,17 +291,18 @@ message GetResponse {
       // Object metadata headers
       Header header = 3;
     }
-    // Single message in the response stream.
-    oneof object_part {
-      // Initial part of the object stream
-      Init init = 1;
 
-      // Chunked object payload
-      bytes chunk = 2;
+    // Initial part of the object stream. Mutually exclusive with `split_info`
+    // and, for requests with `meta_header.version` <= 2.17, with `chunk`.
+    Init init = 1;
 
-      // Meta information of split hierarchy for object assembly.
-      SplitInfo split_info = 3;
-    }
+    // Chunked object payload. Mutually exclusive with `split_info` and, for
+    // requests with `meta_header.version` <= 2.17, `init`.
+    bytes chunk = 2;
+
+    // Meta information of split hierarchy for object assembly. Mutually
+    // exclusive with `init` and `chunk`.
+    SplitInfo split_info = 3;
   }
   // Body of get object response message.
   Body body = 1;
diff --git a/proto-docs/object.md b/proto-docs/object.md
index b289b623..c24b5064 100644
--- a/proto-docs/object.md
+++ b/proto-docs/object.md
@@ -569,9 +569,9 @@ GET Object Response body
 
 | Field | Type | Label | Description |
 | ----- | ---- | ----- | ----------- |
-| init | [GetResponse.Body.Init](#neo.fs.v2.object.GetResponse.Body.Init) |  | Initial part of the object stream |
-| chunk | [bytes](#bytes) |  | Chunked object payload |
-| split_info | [SplitInfo](#neo.fs.v2.object.SplitInfo) |  | Meta information of split hierarchy for object assembly. |
+| init | [GetResponse.Body.Init](#neo.fs.v2.object.GetResponse.Body.Init) |  | Initial part of the object stream. Mutually exclusive with `split_info` and, for requests with `meta_header.version` <= 2.17, with `chunk`. |
+| chunk | [bytes](#bytes) |  | Chunked object payload. Mutually exclusive with `split_info` and, for requests with `meta_header.version` <= 2.17, `init`. |
+| split_info | [SplitInfo](#neo.fs.v2.object.SplitInfo) |  | Meta information of split hierarchy for object assembly. Mutually exclusive with `init` and `chunk`. |
 
 
 <a name="neo.fs.v2.object.GetResponse.Body.Init"></a>