diff --git a/arch/cris/arch-v10/drivers/sync_serial.c b/arch/cris/arch-v10/drivers/sync_serial.c
index d2ad9e7a1738..466af40c5822 100644
--- a/arch/cris/arch-v10/drivers/sync_serial.c
+++ b/arch/cris/arch-v10/drivers/sync_serial.c
@@ -158,7 +158,7 @@ static int sync_serial_open(struct inode *inode, struct file *file);
 static int sync_serial_release(struct inode *inode, struct file *file);
 static unsigned int sync_serial_poll(struct file *filp, poll_table *wait);
 
-static int sync_serial_ioctl(struct file *file,
+static long sync_serial_ioctl(struct file *file,
 	unsigned int cmd, unsigned long arg);
 static ssize_t sync_serial_write(struct file *file, const char *buf,
 	size_t count, loff_t *ppos);