diff --git a/libcpu/arm/cortex-m3/cpuport.c b/libcpu/arm/cortex-m3/cpuport.c
index 055afda43c..af41a79f6a 100644
--- a/libcpu/arm/cortex-m3/cpuport.c
+++ b/libcpu/arm/cortex-m3/cpuport.c
@@ -64,7 +64,7 @@ rt_uint8_t *rt_hw_stack_init(void *tentry, void *parameter,
 	return (rt_uint8_t *)stk;
 }
 
-extern void list_thread(void);
+extern long list_thread(void);
 extern rt_thread_t rt_current_thread;
 /**
  * fault exception handling
diff --git a/libcpu/arm/cortex-m4/cpuport.c b/libcpu/arm/cortex-m4/cpuport.c
index 5f81462d1e..b8f00a7675 100644
--- a/libcpu/arm/cortex-m4/cpuport.c
+++ b/libcpu/arm/cortex-m4/cpuport.c
@@ -125,7 +125,7 @@ rt_uint8_t *rt_hw_stack_init(void *tentry, void *parameter,
 }
 
 extern void rt_hw_interrupt_thread_switch(void);
-extern void list_thread(void);
+extern long list_thread(void);
 extern rt_thread_t rt_current_thread;
 void rt_hw_hard_fault_exception(struct exception_stack_frame * exception_stack)
 {
diff --git a/libcpu/arm/lpc1100/fault.c b/libcpu/arm/lpc1100/fault.c
index 5b8dc6b62f..d1fe68eefc 100644
--- a/libcpu/arm/lpc1100/fault.c
+++ b/libcpu/arm/lpc1100/fault.c
@@ -26,7 +26,7 @@ struct stack_contex
 };
 
 extern void rt_hw_interrupt_thread_switch(void);
-extern void list_thread(void);
+extern long list_thread(void);
 extern rt_thread_t rt_current_thread;
 void rt_hw_hard_fault_exception(struct stack_contex* contex)
 {
diff --git a/libcpu/arm/lpc122x/fault.c b/libcpu/arm/lpc122x/fault.c
index 5b8dc6b62f..d1fe68eefc 100644
--- a/libcpu/arm/lpc122x/fault.c
+++ b/libcpu/arm/lpc122x/fault.c
@@ -26,7 +26,7 @@ struct stack_contex
 };
 
 extern void rt_hw_interrupt_thread_switch(void);
-extern void list_thread(void);
+extern long list_thread(void);
 extern rt_thread_t rt_current_thread;
 void rt_hw_hard_fault_exception(struct stack_contex* contex)
 {
diff --git a/libcpu/arm/nuc1xx/fault.c b/libcpu/arm/nuc1xx/fault.c
index 5b8dc6b62f..d1fe68eefc 100644
--- a/libcpu/arm/nuc1xx/fault.c
+++ b/libcpu/arm/nuc1xx/fault.c
@@ -26,7 +26,7 @@ struct stack_contex
 };
 
 extern void rt_hw_interrupt_thread_switch(void);
-extern void list_thread(void);
+extern long list_thread(void);
 extern rt_thread_t rt_current_thread;
 void rt_hw_hard_fault_exception(struct stack_contex* contex)
 {