diff --git a/protobuf/v1/pool.proto b/protobuf/v1/pool.proto
index 9e74b455..6c87a324 100644
--- a/protobuf/v1/pool.proto
+++ b/protobuf/v1/pool.proto
@@ -36,6 +36,9 @@ message CreatePoolRequest {
   google.protobuf.StringValue uuid = 2; // optional uuid for the pool to be created
   repeated string disks = 3; // disk device paths or URIs to be claimed by the pool
   PoolType pooltype = 4;     // type of the pool
+  // Default cluster size is 4MiB (4 * 1024 * 1024), input cluster size must be multiple of 1MiB, 
+  // else default cluster size will be considered.
+  optional uint32 cluster_size = 5;
 }
 
 // Create pool arguments.
@@ -64,6 +67,7 @@ message Pool {
   uint64 used = 6;            // used bytes from the pool
   PoolType pooltype = 7;      // type of the pool
   uint64 committed = 8;       // committed size of all pool replicas (sum of capacities of all replicas)
+  uint32 cluster_size = 9;    // blobstor cluster size set during pool creation
 }
 
 // Destroy pool arguments.