diff --git a/basis/math/vectors/vectors.factor b/basis/math/vectors/vectors.factor
index 5316720b2f..01a421b4e7 100644
--- a/basis/math/vectors/vectors.factor
+++ b/basis/math/vectors/vectors.factor
@@ -25,7 +25,7 @@ IN: math.vectors
 : normalize ( u -- v ) dup norm v/n ;
 
 : set-axis ( u v axis -- w )
-    [ >r zero? 2over ? r> swap nth ] map-index 2nip ;
+    [ [ zero? 2over ? ] dip swap nth ] map-index 2nip ;
 
 HINTS: vneg { array } ;
 HINTS: norm-sq { array } ;