diff --git a/hadoop-ozone/common/src/main/proto/OzoneManagerProtocol.proto b/hadoop-ozone/common/src/main/proto/OzoneManagerProtocol.proto
index 242e3b5b83..975c790f78 100644
--- a/hadoop-ozone/common/src/main/proto/OzoneManagerProtocol.proto
+++ b/hadoop-ozone/common/src/main/proto/OzoneManagerProtocol.proto
@@ -324,7 +324,7 @@ message AllocateBlockRequest {
 
 message AllocateBlockResponse {
     required Status status = 1;
-    required KeyLocation keyLocation = 2;
+    optional KeyLocation keyLocation = 2;
 }
 
 message CommitKeyRequest {