diff --git a/system/HTTP/URI.php b/system/HTTP/URI.php
index efa99cf778a8..d0d23a3d26ee 100644
--- a/system/HTTP/URI.php
+++ b/system/HTTP/URI.php
@@ -1177,7 +1177,8 @@ protected function parseStr(string $query): array
         parse_str($params, $result);
 
         foreach ($result as $key => $value) {
-            $return[hex2bin($key)] = $value;
+            // Array key might be int
+            $return[hex2bin((string) $key)] = $value;
         }
 
         return $return;