diff --git a/alfa-xdomea/src/main/java/de/ozgcloud/alfa/common/DateConverter.java b/alfa-xdomea/src/main/java/de/ozgcloud/alfa/common/DateConverter.java
index 20e9f11df94b26f6a257711ae78a6ca1019f3568..d2058d91426c4c70004aae05f9dd5f47fc3bee41 100644
--- a/alfa-xdomea/src/main/java/de/ozgcloud/alfa/common/DateConverter.java
+++ b/alfa-xdomea/src/main/java/de/ozgcloud/alfa/common/DateConverter.java
@@ -26,11 +26,13 @@ public class DateConverter {
 
 	public Optional<XMLGregorianCalendar> convertGermanFormatToISO(String dateStr) {
 		try {
-			return Optional.of(createDatatypeFactory().newXMLGregorianCalendar(LocalDate.parse(dateStr, DATE_TIME_FORMATTER).toString()));
+			if (nonNull(dateStr)) {
+				return Optional.of(createDatatypeFactory().newXMLGregorianCalendar(LocalDate.parse(dateStr, DATE_TIME_FORMATTER).toString()));
+			}
 		} catch (Exception e) {
 			LOG.warn("Date '{}' cannot be converted to ISO format.", dateStr, e);
-			return Optional.empty();
 		}
+		return Optional.empty();
 	}
 
 	public XMLGregorianCalendar toXmlGregorianCalendar(ZonedDateTime date) {