diff --git a/porting/liteos_m/kernel/include/bits/alltypes.h b/porting/liteos_m/kernel/include/bits/alltypes.h
index 0909a3955e8bb64189122c5b7ade407c30af7783..2d10e80a2ede94b3b96f178a08ec521a440c175b 100644
--- a/porting/liteos_m/kernel/include/bits/alltypes.h
+++ b/porting/liteos_m/kernel/include/bits/alltypes.h
@@ -496,7 +496,7 @@ typedef struct __locale_struct * locale_t;
 
 
 #if defined(__NEED_sigset_t) && !defined(__DEFINED_sigset_t)
-typedef struct __sigset_t { unsigned long __bits[128/sizeof(long)]; } sigset_t;
+typedef unsigned long sigset_t;
 #define __DEFINED_sigset_t
 #endif
 
diff --git a/porting/liteos_m/kernel/include/signal.h b/porting/liteos_m/kernel/include/signal.h
index c3848a9881c933e39baf895a834864070d99325f..fbdf667b2f202ab2f1375952ce9d4cf636ef1ce0 100644
--- a/porting/liteos_m/kernel/include/signal.h
+++ b/porting/liteos_m/kernel/include/signal.h
@@ -1,43 +1,6 @@
 #ifndef _SIGNAL_H
 #define _SIGNAL_H
 
-#ifdef __ICCARM__ /* for iar */
-
-#include_next <signal.h>
-
-#ifdef __cplusplus
-extern "C" {
-#endif
-
-#define __NEED_pthread_attr_t
-#define __NEED_time_t
-
-#include <bits/alltypes.h>
-
-union sigval {
-	int sival_int;
-	void *sival_ptr;
-};
-
-struct sigevent {
-	union sigval sigev_value;
-	int sigev_signo;
-	int sigev_notify;
-	void (*sigev_notify_function)(union sigval);
-	pthread_attr_t *sigev_notify_attributes;
-	char __pad[56-3*sizeof(long)];
-};
-
-#define SIGEV_SIGNAL 0
-#define SIGEV_NONE 1
-#define SIGEV_THREAD 2
-
-#ifdef __cplusplus
-}
-#endif
-
-#else
-
 #ifdef __cplusplus
 extern "C" {
 #endif
@@ -320,5 +283,4 @@ __REDIR(sigtimedwait, __sigtimedwait_time64);
 }
 #endif
 
-#endif /* __ICCARM__ */
 #endif