diff --git a/std/dup2.lb b/std/dup2.lb
index ba91170..93cd90b 100644
--- a/std/dup2.lb
+++ b/std/dup2.lb
@@ -1,5 +1,6 @@
 @ 0
  args 2
+ swap
  push 1
  pick
  push 1
diff --git a/std/dup4.lb b/std/dup4.lb
index 4218f40..99b03a0 100644
--- a/std/dup4.lb
+++ b/std/dup4.lb
@@ -1,5 +1,7 @@
 @ 0
  args 4
+ push 4
+ #exec std/rev.lb
  push 3
  pick
  push 3