diff --git a/ydb/core/blobstorage/nodewarden/node_warden_impl.cpp b/ydb/core/blobstorage/nodewarden/node_warden_impl.cpp
index 7b171bc267bf..8b1f0616540b 100644
--- a/ydb/core/blobstorage/nodewarden/node_warden_impl.cpp
+++ b/ydb/core/blobstorage/nodewarden/node_warden_impl.cpp
@@ -562,7 +562,7 @@ bool NKikimr::ObtainPDiskKey(NPDisk::TMainKey *mainKey, const NKikimrProto::TKey
         const ui8 *key;
         ui32 keySize;
         keys[i].Key.GetKeyBytes(&key, &keySize);
-        Y_VERIFY_DEBUG(keySize == sizeof(ui64));
+        Y_VERIFY_DEBUG(keySize == 4 * sizeof(ui64));
         mainKey->Keys.push_back(*(ui64*)key);
     }
     mainKey->IsInitialized = true;