diff --git a/arch/alpha/kernel/osf_sys.c b/arch/alpha/kernel/osf_sys.c
index 0b961093ca5c..6d76e528ab8f 100644
--- a/arch/alpha/kernel/osf_sys.c
+++ b/arch/alpha/kernel/osf_sys.c
@@ -1290,7 +1290,7 @@ SYSCALL_DEFINE1(old_adjtimex, struct timex32 __user *, txc_p)
 	/* copy relevant bits of struct timex. */
 	if (copy_from_user(&txc, txc_p, offsetof(struct timex32, time)) ||
 	    copy_from_user(&txc.tick, &txc_p->tick, sizeof(struct timex32) - 
-			   offsetof(struct timex32, time)))
+			   offsetof(struct timex32, tick)))
 	  return -EFAULT;
 
 	ret = do_adjtimex(&txc);