diff --git a/src/api/endpoints/class-tainacan-rest-importers-controller.php b/src/api/endpoints/class-tainacan-rest-importers-controller.php
index ba10b92e1..7fa7ffb01 100644
--- a/src/api/endpoints/class-tainacan-rest-importers-controller.php
+++ b/src/api/endpoints/class-tainacan-rest-importers-controller.php
@@ -201,22 +201,6 @@ class REST_Importers_Controller extends REST_Controller {
                     
                     if ($att == 'collection') {
                         if (is_array($value) && isset($value['id'])) {
-
-                            if(isset($value['mapping']) && is_array($value['mapping'])){
-                                foreach( $value['mapping'] as $metadatum_id => $header ){
-
-                                    if( !is_numeric($metadatum_id) ) {
-                                        $metadatum = $importer->create_new_metadata( $header, $value['id']);
-
-                                        if( is_object($metadatum) ){
-                                            unset($value['mapping'][$metadatum_id]);
-                                            $value['mapping'][$metadatum->get_id()] = $header;
-                                        }
-
-                                    }
-                                }
-                            }
-
                             $importer->add_collection($value);
                             continue;
                         } else {
diff --git a/src/importer/class-tainacan-csv.php b/src/importer/class-tainacan-csv.php
index ec39835aa..aa6203fdf 100644
--- a/src/importer/class-tainacan-csv.php
+++ b/src/importer/class-tainacan-csv.php
@@ -715,6 +715,20 @@ class CSV extends Importer {
         if (isset($collection['id'])) {
 
             if( isset($collection['mapping']) && is_array($collection['mapping']) ){
+
+                foreach( $collection['mapping'] as $metadatum_id => $header ){
+
+                    if( !is_numeric($metadatum_id) ) {
+                        $metadatum = $this->create_new_metadata( $header, $collection['id']);
+
+                        if( is_object($metadatum) ){
+                            unset($collection['mapping'][$metadatum_id]);
+                            $collection['mapping'][$metadatum->get_id()] = $header;
+                        }
+
+                    }
+                }
+
                 $this->save_mapping( $collection['id'], $collection['mapping'] );
             }