diff --git a/src/PhpSpreadsheet/Reader/Xlsx/DataValidations.php b/src/PhpSpreadsheet/Reader/Xlsx/DataValidations.php
index 41a8c9fb..3e9c8787 100644
--- a/src/PhpSpreadsheet/Reader/Xlsx/DataValidations.php
+++ b/src/PhpSpreadsheet/Reader/Xlsx/DataValidations.php
@@ -34,10 +34,10 @@ class DataValidations
                     $docValidation->setType((string) $dataValidation['type']);
                     $docValidation->setErrorStyle((string) $dataValidation['errorStyle']);
                     $docValidation->setOperator((string) $dataValidation['operator']);
-                    $docValidation->setAllowBlank($dataValidation['allowBlank'] != 0);
-                    $docValidation->setShowDropDown($dataValidation['showDropDown'] == 0);
-                    $docValidation->setShowInputMessage($dataValidation['showInputMessage'] != 0);
-                    $docValidation->setShowErrorMessage($dataValidation['showErrorMessage'] != 0);
+                    $docValidation->setAllowBlank(filter_var($dataValidation['allowBlank'], FILTER_VALIDATE_BOOLEAN));
+                    $docValidation->setShowDropDown(filter_var($dataValidation['showDropDown'], FILTER_VALIDATE_BOOLEAN));
+                    $docValidation->setShowInputMessage(filter_var($dataValidation['showInputMessage'], FILTER_VALIDATE_BOOLEAN));
+                    $docValidation->setShowErrorMessage(filter_var($dataValidation['showErrorMessage'], FILTER_VALIDATE_BOOLEAN));
                     $docValidation->setErrorTitle((string) $dataValidation['errorTitle']);
                     $docValidation->setError((string) $dataValidation['error']);
                     $docValidation->setPromptTitle((string) $dataValidation['promptTitle']);
diff --git a/src/PhpSpreadsheet/Writer/Xlsx/Worksheet.php b/src/PhpSpreadsheet/Writer/Xlsx/Worksheet.php
index 1d8d67d7..ec6cd8cb 100644
--- a/src/PhpSpreadsheet/Writer/Xlsx/Worksheet.php
+++ b/src/PhpSpreadsheet/Writer/Xlsx/Worksheet.php
@@ -699,7 +699,7 @@ class Worksheet extends WriterPart
                 }
 
                 $objWriter->writeAttribute('allowBlank', ($dv->getAllowBlank() ? '1' : '0'));
-                $objWriter->writeAttribute('showDropDown', (!$dv->getShowDropDown() ? '1' : '0'));
+                $objWriter->writeAttribute('showDropDown', ($dv->getShowDropDown() ? '1' : '0'));
                 $objWriter->writeAttribute('showInputMessage', ($dv->getShowInputMessage() ? '1' : '0'));
                 $objWriter->writeAttribute('showErrorMessage', ($dv->getShowErrorMessage() ? '1' : '0'));