diff --git a/files/converter/unoconv/classes/converter.php b/files/converter/unoconv/classes/converter.php
index 7ce7c05683d..c364bc9ec84 100644
--- a/files/converter/unoconv/classes/converter.php
+++ b/files/converter/unoconv/classes/converter.php
@@ -197,6 +197,9 @@ class converter implements \core_files\converter_interface {
         }
 
         $conversions = conversion::get_conversions_for_file($testdocx, $format);
+        foreach ($conversions as $conversion) {
+            $conversion->delete();
+        }
 
         $conversion = new conversion(0, (object) [
                 'sourcefileid' => $testdocx->get_id(),