diff --git a/deps/oblib/src/lib/ob_define.h b/deps/oblib/src/lib/ob_define.h
index 6492b709c2..f2cc1425b2 100644
--- a/deps/oblib/src/lib/ob_define.h
+++ b/deps/oblib/src/lib/ob_define.h
@@ -1670,7 +1670,7 @@ OB_INLINE bool is_bootstrap_resource_pool(const uint64_t resource_pool_id)
 const int64_t OB_MALLOC_NORMAL_BLOCK_SIZE = (1LL << 13) - 256;                 // 8KB
 const int64_t OB_MALLOC_MIDDLE_BLOCK_SIZE = (1LL << 16) - 128;                 // 64KB
 const int64_t OB_MALLOC_BIG_BLOCK_SIZE = (1LL << 21) - ACHUNK_PRESERVE_SIZE;// 2MB (-17KB)
-const int64_t OB_MALLOC_REQ_NORMAL_BLOCK_SIZE = (256LL << 10);                 // 256KB
+const int64_t OB_MALLOC_REQ_NORMAL_BLOCK_SIZE = (240LL << 10);                 // 240KB
 
 const int64_t OB_MAX_MYSQL_RESPONSE_PACKET_SIZE = OB_MALLOC_BIG_BLOCK_SIZE;