diff --git a/arch/um/drivers/line.c b/arch/um/drivers/line.c
index 14a102e..cf8a97f 100644
--- a/arch/um/drivers/line.c
+++ b/arch/um/drivers/line.c
@@ -5,6 +5,7 @@
 
 #include "linux/irqreturn.h"
 #include "linux/kd.h"
+#include "linux/sched.h"
 #include "chan_kern.h"
 #include "irq_kern.h"
 #include "irq_user.h"