diff --git a/src/lsr/las3r.core.lsr b/src/lsr/las3r.core.lsr
index 6e88748..7d8d5c7 100644
--- a/src/lsr/las3r.core.lsr
+++ b/src/lsr/las3r.core.lsr
@@ -1485,8 +1485,10 @@
   "Returns a lazy seq of the first item in each coll, then the second
   etc."
   [& colls]
-  (apply concat (apply map list colls)))
-
+  (let [fc (first colls)]
+    (when (seq fc)
+      (lazy-cons (first fc)
+                 (apply interleave (concat (rest colls) [(rest fc)]))))))
 
 (defn nthrest
   "Returns the nth rest of coll, (seq coll) when n is 0."