diff --git a/bsp/imxrt1052-evk/applications/SConscript b/bsp/imxrt1052-evk/applications/SConscript
index 79416cbc8..7725e3b91 100644
--- a/bsp/imxrt1052-evk/applications/SConscript
+++ b/bsp/imxrt1052-evk/applications/SConscript
@@ -7,9 +7,7 @@ src	= Glob('*.c')
 CPPPATH = [cwd, str(Dir('#'))]
 
 # add for startup script 
-if rtconfig.CROSS_TOOL == 'iar':
-    CPPDEFINES = ['_TIMESPEC_DEFINED']
-elif rtconfig.CROSS_TOOL == 'gcc':
+if rtconfig.CROSS_TOOL == 'gcc':
     CPPDEFINES = ['__START=entry']
 else:
     CPPDEFINES = []
diff --git a/bsp/lpc54608-LPCXpresso/applications/SConscript b/bsp/lpc54608-LPCXpresso/applications/SConscript
index ce2232217..01eb940df 100644
--- a/bsp/lpc54608-LPCXpresso/applications/SConscript
+++ b/bsp/lpc54608-LPCXpresso/applications/SConscript
@@ -6,12 +6,6 @@ cwd     = os.path.join(str(Dir('#')), 'applications')
 src	= Glob('*.c')
 CPPPATH = [cwd, str(Dir('#'))]
 
-# add for startup script 
-if rtconfig.CROSS_TOOL == 'iar':
-    CPPDEFINES = ['_TIMESPEC_DEFINED']
-else:
-    CPPDEFINES = []
-
-group = DefineGroup('Applications', src, depend = [''], CPPPATH = CPPPATH, CPPDEFINES=CPPDEFINES)
+group = DefineGroup('Applications', src, depend = [''], CPPPATH = CPPPATH)
 
 Return('group')