diff --git a/drivers/net/sundance.c b/drivers/net/sundance.c
index feaf0e0..43695b7 100644
--- a/drivers/net/sundance.c
+++ b/drivers/net/sundance.c
@@ -909,7 +909,7 @@
 			printk(KERN_INFO "%s: Setting %s-duplex based on MII #%d "
 				   "negotiated capability %4.4x.\n", dev->name,
 				   duplex ? "full" : "half", np->phys[0], negotiated);
-		iowrite16(ioread16(ioaddr + MACCtrl0) | duplex ? 0x20 : 0, ioaddr + MACCtrl0);
+		iowrite16(ioread16(ioaddr + MACCtrl0) | (duplex ? 0x20 : 0), ioaddr + MACCtrl0);
 	}
 }