diff --git a/src/Spout/Writer/XLSX/Internal/Worksheet.php b/src/Spout/Writer/XLSX/Internal/Worksheet.php
index 2e1c929..3ffd97b 100644
--- a/src/Spout/Writer/XLSX/Internal/Worksheet.php
+++ b/src/Spout/Writer/XLSX/Internal/Worksheet.php
@@ -146,11 +146,7 @@ EOD;
$cellXML .= ' t="s">' . $sharedStringId . '';
}
} else if (CellHelper::isBoolean($cellValue)) {
- if ($cellValue === true) {
- $cellXML .= ' t="b">1';
- } else {
- $cellXML .= ' t="b">0';
- }
+ $cellXML .= ' t="b">' . intval($cellValue) . '';
} else if (CellHelper::isNumeric($cellValue)) {
$cellXML .= '>' . $cellValue . '';
} else if (empty($cellValue)) {