diff --git a/src/Services/ImportExportSystem/PartKeeprImporter/PKImportHelperTrait.php b/src/Services/ImportExportSystem/PartKeeprImporter/PKImportHelperTrait.php
index 05137227..a318c281 100644
--- a/src/Services/ImportExportSystem/PartKeeprImporter/PKImportHelperTrait.php
+++ b/src/Services/ImportExportSystem/PartKeeprImporter/PKImportHelperTrait.php
@@ -86,7 +86,7 @@ trait PKImportHelperTrait
         if (empty($attachment_row['extension'])) {
             //Use mime type to determine the extension like PartKeepr does in legacy implementation (just use the second part of the mime type)
             //See UploadedFile.php:291 in PartKeepr (https://github.com/partkeepr/PartKeepr/blob/f6176c3354b24fa39ac8bc4328ee0df91de3d5b6/src/PartKeepr/UploadedFileBundle/Entity/UploadedFile.php#L291)
-            if (empty ($attachment_row['mimetype'])) {
+            if (!empty ($attachment_row['mimetype'])) {
                 $attachment_row['extension'] = explode('/', $attachment_row['mimetype'])[1];
             } else {
                 //If the mime type is empty, we use the original extension