diff --git a/drivers/net/wan/hdlc_x25.c b/drivers/net/wan/hdlc_x25.c
index 63c9aeed9a34..c84536b03aa8 100644
--- a/drivers/net/wan/hdlc_x25.c
+++ b/drivers/net/wan/hdlc_x25.c
@@ -253,7 +253,7 @@ static int x25_ioctl(struct net_device *dev, struct ifreq *ifr)
 			return -EBUSY;
 
 		/* backward compatibility */
-		if (ifr->ifr_settings.size = 0) {
+		if (ifr->ifr_settings.size == 0) {
 			new_settings.dce = 0;
 			new_settings.modulo = 8;
 			new_settings.window = 7;