diff --git a/test/functional/api/cas/cli_messages.py b/test/functional/api/cas/cli_messages.py
index 78da17b..eb7e0de 100644
--- a/test/functional/api/cas/cli_messages.py
+++ b/test/functional/api/cas/cli_messages.py
@@ -1,6 +1,6 @@
 #
 # Copyright(c) 2019-2022 Intel Corporation
-# Copyright(c) 2024 Huawei Technologies
+# Copyright(c) 2024-2025 Huawei Technologies
 # SPDX-License-Identifier: BSD-3-Clause
 #
 
@@ -233,6 +233,12 @@ malformed_io_class_header = [
 
 unexpected_cls_option = [r"Option '--cache-line-size \(-x\)' is not allowed"]
 
+attach_not_enough_memory = [
+    r"Not enough free RAM\.\nYou need at least \d+.\d+GB to attach a device to cache "
+    r"with cache line size equal \d+kB.\n"
+    r"Try with greater cache line size\."
+]
+
 
 def check_stderr_msg(output: Output, expected_messages, negate=False):
     return __check_string_msg(output.stderr, expected_messages, negate)