diff --git a/lib/Twig/Extension/Core.php b/lib/Twig/Extension/Core.php
index ef3657698..b34728c1d 100644
--- a/lib/Twig/Extension/Core.php
+++ b/lib/Twig/Extension/Core.php
@@ -692,7 +692,16 @@ function twig_array_merge($arr1, $arr2)
 function twig_slice(Twig_Environment $env, $item, $start, $length = null, $preserveKeys = false)
 {
     if ($item instanceof Traversable) {
-        $item = iterator_to_array($item, false);
+
+        if ($item instanceof IteratorAggregate) {
+            $item = $item->getIterator();
+        }
+
+        if ($start >= 0 && $length >= 0) {
+            return iterator_to_array(new LimitIterator($item, $start, $length), $preserveKeys);
+        }
+
+        $item = iterator_to_array($item, $preserveKeys);
     }
 
     if (is_array($item)) {