diff --git a/drivers/sbus/char/cpwatchdog.c b/drivers/sbus/char/cpwatchdog.c
index 235703414370..23abfdfb44f1 100644
--- a/drivers/sbus/char/cpwatchdog.c
+++ b/drivers/sbus/char/cpwatchdog.c
@@ -279,6 +279,7 @@ static inline int wd_opt_timeout(void)
 
 static int wd_open(struct inode *inode, struct file *f)
 {
+	lock_kernel();
 	switch(iminor(inode))
 	{
 		case WD0_MINOR:
@@ -291,6 +292,7 @@ static int wd_open(struct inode *inode, struct file *f)
 			f->private_data = &wd_dev.watchdog[WD2_ID];
 			break;
 		default:
+			unlock_kernel();
 			return(-ENODEV);
 	}
 
@@ -304,11 +306,13 @@ static int wd_open(struct inode *inode, struct file *f)
 						(void *)wd_dev.regs)) {
 			printk("%s: Cannot register IRQ %d\n", 
 				WD_OBPNAME, wd_dev.irq);
+			unlock_kernel();
 			return(-EBUSY);
 		}
 		wd_dev.initialized = 1;
 	}
 
+	unlock_kernel();
 	return(nonseekable_open(inode, f));
 }