diff --git a/converter/src/main/java/lcsb/mapviewer/converter/annotation/XmlAnnotationParser.java b/converter/src/main/java/lcsb/mapviewer/converter/annotation/XmlAnnotationParser.java
index 4c811618c5ef54550290dcaa292a9faf0018a8a7..c5fda22de6cfac76ea539d8167f3755d6cda098f 100644
--- a/converter/src/main/java/lcsb/mapviewer/converter/annotation/XmlAnnotationParser.java
+++ b/converter/src/main/java/lcsb/mapviewer/converter/annotation/XmlAnnotationParser.java
@@ -320,8 +320,12 @@ public class XmlAnnotationParser {
     result.append("<rdf:Bag>\n");
     result.append("<rdf:li rdf:parseType=\"Resource\">\n");
     result.append("<vCard:N rdf:parseType=\"Resource\">\n");
-    result.append("<vCard:Family>" + XmlParser.escapeXml(author.getLastName()) + "</vCard:Family>\n");
-    result.append("<vCard:Given>" + XmlParser.escapeXml(author.getFirstName()) + "</vCard:Given>\n");
+    if (author.getLastName() != null) {
+      result.append("<vCard:Family>" + XmlParser.escapeXml(author.getLastName()) + "</vCard:Family>\n");
+    }
+    if (author.getFirstName() != null) {
+      result.append("<vCard:Given>" + XmlParser.escapeXml(author.getFirstName()) + "</vCard:Given>\n");
+    }
     result.append("</vCard:N>\n");
 
     if (author.getEmail() != null && !author.getEmail().trim().isEmpty()) {