diff --git a/sys/compat/linuxkpi/common/include/linux/sched.h b/sys/compat/linuxkpi/common/include/linux/sched.h
--- a/sys/compat/linuxkpi/common/include/linux/sched.h
+++ b/sys/compat/linuxkpi/common/include/linux/sched.h
@@ -41,6 +41,7 @@
 #include <linux/bitmap.h>
 #include <linux/compat.h>
 #include <linux/completion.h>
+#include <linux/hrtimer.h>
 #include <linux/mm_types.h>
 #include <linux/pid.h>
 #include <linux/slab.h>
@@ -61,6 +62,8 @@
 
 #define	TASK_COMM_LEN		(MAXCOMLEN + 1)
 
+struct seq_file;
+
 struct work_struct;
 struct task_struct {
 	struct thread *task_thread;