diff --git a/application/threadx/demo/Makefile b/application/threadx/demo/Makefile
index fbd2767a..483c065e 100644
--- a/application/threadx/demo/Makefile
+++ b/application/threadx/demo/Makefile
@@ -2,9 +2,11 @@ TARGET = threadx_demo
 RTOS = ThreadX
 
 # define TX_INCLUDE_USER_DEFINE_FILE to include user defines in tx_user.h
-# -fno-tree-tail-merge option is required with >O1 for ThreadX source code correct compiling
+COMMON_FLAGS := -O2 -DTX_INCLUDE_USER_DEFINE_FILE
+
+# -fno-tree-tail-merge option is required with >O1 for ThreadX source code correct compiling for gcc
 # eg. OS/ThreadX/common/src/tx_mutex_delete.c
-COMMON_FLAGS := -O2 -fno-tree-tail-merge -DTX_INCLUDE_USER_DEFINE_FILE
+-include toolchain_$(TOOLCHAIN).mk
 
 NUCLEI_SDK_ROOT = ../../..
 
diff --git a/application/threadx/demo/npk.yml b/application/threadx/demo/npk.yml
index 544010b1..a469f223 100644
--- a/application/threadx/demo/npk.yml
+++ b/application/threadx/demo/npk.yml
@@ -21,7 +21,7 @@ dependencies:
 ## Package Configurations
 configuration:
   app_commonflags:
-    value: -O2 -fno-tree-tail-merge -DTX_INCLUDE_USER_DEFINE_FILE
+    value: -O2 -DTX_INCLUDE_USER_DEFINE_FILE
     type: text
     description: Application Compile Flags
 
@@ -44,3 +44,7 @@ buildconfig:
   - type: common
     common_flags: # flags need to be combined together across all packages
       - flags: ${app_commonflags}
+  - type: gcc
+    common_flags:
+      # -fno-tree-tail-merge is required > O1 optimization level case
+      - flags: -fno-tree-tail-merge