diff --git a/src/main/java/cokr/xit/base/docs/xls/XLSReader.java b/src/main/java/cokr/xit/base/docs/xls/XLSReader.java
index bb856a9..10bce83 100644
--- a/src/main/java/cokr/xit/base/docs/xls/XLSReader.java
+++ b/src/main/java/cokr/xit/base/docs/xls/XLSReader.java
@@ -18,6 +18,13 @@ import org.apache.poi.xssf.usermodel.XSSFWorkbook;
 import cokr.xit.foundation.util.DateFormats;
 
 public class XLSReader extends XLS {
+	private boolean xlsx;
+
+	public XLSReader xlsx(boolean xlsx) {
+		this.xlsx = xlsx;
+		return this;
+	}
+
 	public XLSReader open(InputStream input) {
 		load(input);
 		return this;
@@ -30,6 +37,8 @@ public class XLSReader extends XLS {
 
 	@Override
 	protected Workbook newWorkbook(InputStream input) throws Exception {
+		if (xlsx)
+			return super.newWorkbook(input);
 		if (input == null)
 			return new SXSSFWorkbook(rowAccessWindowSize);