diff --git a/src/ImportCsvHandler.php b/src/ImportCsvHandler.php
index d41a4b8..7ae5d39 100644
--- a/src/ImportCsvHandler.php
+++ b/src/ImportCsvHandler.php
@@ -221,7 +221,7 @@ public function getCsvColumnsData($startRow = 0, $endRow = 10)
                 if (\Yii::$app->charset != $this->csv_source_charset) {
                     $encodedData = [];
                     foreach ($data as $row) {
-                        $row = iconv($this->csv_source_charset, \Yii::$app->charset, $row);
+                        $row = iconv($this->csv_source_charset, \Yii::$app->charset, (string) $row);
                         $encodedData[] = $row;
                     }