diff --git a/source/module/monitor_trace.h b/source/module/monitor_trace.h
index e940b86..a3932a9 100644
--- a/source/module/monitor_trace.h
+++ b/source/module/monitor_trace.h
@@ -1,3 +1,6 @@
+#ifndef MODULE_MONITOR_TRACE_H
+#define MODULE_MONITOR_TRACE_H
+
 #include <linux/kernfs.h>
 #include <linux/sched.h>
 
@@ -130,3 +133,5 @@ extern unsigned int (*orig_stack_trace_save_tsk)(struct task_struct *task,
                                                  unsigned int size,
                                                  unsigned int skipnr);
 extern struct task_struct *(*orig_find_task_by_vpid)(pid_t nr);
+
+#endif /* MODULE_MONITOR_TRACE_H */
\ No newline at end of file