diff --git a/src/ArrayFile.php b/src/ArrayFile.php
index b43c6f7..9ee3fce 100644
--- a/src/ArrayFile.php
+++ b/src/ArrayFile.php
@@ -180,7 +180,7 @@ public function set($key, $value = null)
      */
     protected function makeArrayItem(string $key, string $valueType, $value): ArrayItem
     {
-        return (str_contains($key, '.'))
+        return (strpos($key, '.') !== false)
             ? $this->makeAstArrayRecursive($key, $valueType, $value)
             : new ArrayItem(
                 $this->makeAstNode($valueType, $value),