diff --git a/drivers/scsi/ultrastor.c b/drivers/scsi/ultrastor.c
index 9f4b58b..7e22b73 100644
--- a/drivers/scsi/ultrastor.c
+++ b/drivers/scsi/ultrastor.c
@@ -307,7 +307,7 @@
 	"0: bsfw %1,%w0\n\t"
 	"btr %0,%1\n\t"
 	"jnc 0b"
-	: "=&r" (rv), "=m" (*field) :);
+	: "=&r" (rv), "+m" (*field) :);
 
   return rv;
 }