diff --git a/History.md b/History.md
index bff0b351..820a23b2 100644
--- a/History.md
+++ b/History.md
@@ -1,7 +1,9 @@
+- allow 2.1 in RDF metadata in validation for Referenzprofil XRechnung's v 2.1.1
 - log whether a XML or a PDF file was validated
-- XR improvements PR 261 e.g.  Allowing the XRechnung version to be explicitly set in the PDF
+- XR improvements PR 261 e.g. allowing the XRechnung version to be explicitly set in the PDF
 - allow to specify a tradeparties' legalorganisation i.e. allow to write Factur-X invoices to french authorities 
-2.4.0
+
+- 2.4.0
 =======
 2022-01-13
 
diff --git a/validator/src/main/java/org/mustangproject/validator/PDFValidator.java b/validator/src/main/java/org/mustangproject/validator/PDFValidator.java
index a459fb81..a110f783 100644
--- a/validator/src/main/java/org/mustangproject/validator/PDFValidator.java
+++ b/validator/src/main/java/org/mustangproject/validator/PDFValidator.java
@@ -240,7 +240,7 @@ public class PDFValidator extends Validator {
 
 			boolean versionValid=false;
 			for (int i = 0; i < nodes.getLength(); i++) {
-				final String[] valueArray = { "1.0", "2p0", "1.2", "2.0" }; //1.2 and 2.0 are for xrechnung 1.2, 2p0 can be ZF 2.0, 2.1, 2.1.1
+				final String[] valueArray = { "1.0", "2p0", "1.2", "2.0" , "2.1" }; //1.2, 2.0 and 2.1 are for xrechnung 1.2, 2p0 can be ZF 2.0, 2.1, 2.1.1
 				if (stringArrayContains(valueArray, nodes.item(i).getTextContent())) {
 					versionValid=true;
 				} // e.g. 1.0