diff --git a/libraries/classes/Plugins/Import/ImportOds.php b/libraries/classes/Plugins/Import/ImportOds.php
index e9c57179e9..f16f5e7df2 100644
--- a/libraries/classes/Plugins/Import/ImportOds.php
+++ b/libraries/classes/Plugins/Import/ImportOds.php
@@ -246,7 +246,8 @@ class ImportOds extends ImportPlugin
      */
     protected function getValue($cell_attrs, $text)
     {
-        if ($_REQUEST['ods_recognize_percentages']
+        if (isset($_REQUEST['ods_recognize_percentages'])
+            && $_REQUEST['ods_recognize_percentages']
             && ! strcmp(
                 'percentage',
                 (string) $cell_attrs['value-type']