diff --git a/CHANGELOG.md b/CHANGELOG.md
index a1497c7d..9d5239f0 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -15,6 +15,7 @@
     * Fixed UI for Pagemedia note when files cannot yet be uploaded ([#798](https://github.com/getgrav/grav-plugin-admin/issues/798))
     * Fixed Submit buttons getting disabled in case of form invalidity disallowing to submit again ([#802](https://github.com/getgrav/grav-plugin-admin/issues/802))
     * Fixed issue when reading the file size setting if set to `0` (in Pagemedia and File fields)
+    * Fixed issue with `file` field in collections that caused unexpected duplication of items ([#775](https://github.com/getgrav/grav-plugin-admin/issues/775)) 
 
 # v1.2.2
 ## 09/08/2016
diff --git a/classes/controller.php b/classes/controller.php
index badbe639..3f77ed3b 100644
--- a/classes/controller.php
+++ b/classes/controller.php
@@ -1937,7 +1937,7 @@ class AdminController
                         $new_data = $files;
                     }
                     if (isset($data['header'][$init_key])) {
-                        $obj->modifyHeader($init_key, array_merge([], $data['header'][$init_key], $new_data));
+                        $obj->modifyHeader($init_key, array_replace_recursive([], $data['header'][$init_key], $new_data));
                     } else {
                         $obj->modifyHeader($init_key, $new_data);
                     }