diff --git a/drivers/net/hamradio/mkiss.c b/drivers/net/hamradio/mkiss.c
index 3e9accf137e7..41b3d83c2ab8 100644
--- a/drivers/net/hamradio/mkiss.c
+++ b/drivers/net/hamradio/mkiss.c
@@ -524,6 +524,7 @@ static void ax_encaps(struct net_device *dev, unsigned char *icp, int len)
 	ax->dev->trans_start = jiffies;
 	ax->xleft = count - actual;
 	ax->xhead = ax->xbuff + actual;
+	spin_unlock_bh(&ax->buflock);
 }
 
 /* Encapsulate an AX.25 packet and kick it into a TTY queue. */