diff --git a/phpstan.neon b/phpstan.neon
index 130cd20..da48cc2 100644
--- a/phpstan.neon
+++ b/phpstan.neon
@@ -11,4 +11,6 @@ parameters:
     ignoreErrors:
         - message: '#it_fails_to_create_an_item_from_an_array_of_pairs\(\)#'
           path: tests/ItemTest.php
+        - message: '#Function http_build_structured_field\(\) has parameter \$data with no value type specified in iterable type iterable.#'
+          path: src/functions.php
     reportUnmatchedIgnoredErrors: true
diff --git a/src/functions.php b/src/functions.php
index 1db8c63..5064479 100644
--- a/src/functions.php
+++ b/src/functions.php
@@ -47,14 +47,12 @@ function http_parse_structured_field(string $type, string $httpValue): Structure
      */
     function http_build_structured_field(string $type, iterable $data): string /* @phptan-ignore-line */
     {
-        $data = [...$data];
-
         return match ($type) {
             'dictionary' => Dictionary::fromPairs($data)->toHttpValue(),
             'parameters' => Parameters::fromPairs($data)->toHttpValue(),
             'list' => OuterList::fromPairs($data)->toHttpValue(),
-            'innerlist' => InnerList::fromPair($data)->toHttpValue(), /* @phpstan-ignore-line */
-            'item' => Item::fromPair($data)->toHttpValue(), /* @phpstan-ignore-line */
+            'innerlist' => InnerList::fromPair([...$data])->toHttpValue(), /* @phpstan-ignore-line */
+            'item' => Item::fromPair([...$data])->toHttpValue(), /* @phpstan-ignore-line */
             default => throw new OutOfBoundsException('The submitted type "'.$type.'" is unknown or not supported,'),  /* @phpstan-ignore-line */
         };
     }