diff --git a/library/src/main/java/org/mustangproject/ZUGFeRD/OXPullProvider.java b/library/src/main/java/org/mustangproject/ZUGFeRD/OXPullProvider.java
index 881bd98b..f2a032f2 100644
--- a/library/src/main/java/org/mustangproject/ZUGFeRD/OXPullProvider.java
+++ b/library/src/main/java/org/mustangproject/ZUGFeRD/OXPullProvider.java
@@ -57,7 +57,7 @@ public class OXPullProvider extends ZUGFeRD2PullProvider {
       paymentTermsDescription = XMLTools.encodeXML(trans.getPaymentTermDescription());
 		}
 
-		if (paymentTermsDescription == null && !trans.getDocumentCode().equals(CORRECTEDINVOICE)/* && (trans.getDocumentCode() != DocumentCodeTypeConstants.CREDITNOTE)*/) {
+		if (paymentTermsDescription == null && !CORRECTEDINVOICE.equals(trans.getDocumentCode())/* && (trans.getDocumentCode() != DocumentCodeTypeConstants.CREDITNOTE)*/) {
 			paymentTermsDescription = "Zahlbar ohne Abzug bis " + germanDateFormat.format(trans.getDueDate());
 
 		}
diff --git a/library/src/main/java/org/mustangproject/ZUGFeRD/ZUGFeRD2PullProvider.java b/library/src/main/java/org/mustangproject/ZUGFeRD/ZUGFeRD2PullProvider.java
index 7c85155c..6efb4b23 100644
--- a/library/src/main/java/org/mustangproject/ZUGFeRD/ZUGFeRD2PullProvider.java
+++ b/library/src/main/java/org/mustangproject/ZUGFeRD/ZUGFeRD2PullProvider.java
@@ -361,8 +361,8 @@ public class ZUGFeRD2PullProvider implements IXMLProvider {
 				paymentTermsDescription += discount.getAsXRechnung();
 			}
 		} else if (paymentTermsDescription == null
-			&& !trans.getDocumentCode().equals(DocumentCodeTypeConstants.CORRECTEDINVOICE)
-			&& !trans.getDocumentCode().equals(DocumentCodeTypeConstants.CREDITNOTE)
+			&& !DocumentCodeTypeConstants.CORRECTEDINVOICE.equals(trans.getDocumentCode())
+			&& !DocumentCodeTypeConstants.CREDITNOTE.equals(trans.getDocumentCode())
 		) {
 			if (trans.getDueDate() != null) {
 				paymentTermsDescription = "Please remit until " + germanDateFormat.format(trans.getDueDate());
@@ -721,8 +721,8 @@ public class ZUGFeRD2PullProvider implements IXMLProvider {
 				}
 			}
 		}
-		if (trans.getDocumentCode().equals(DocumentCodeTypeConstants.CORRECTEDINVOICE)
-			|| trans.getDocumentCode().equals(DocumentCodeTypeConstants.CREDITNOTE)
+		if (DocumentCodeTypeConstants.CORRECTEDINVOICE.equals(trans.getDocumentCode())
+			|| DocumentCodeTypeConstants.CREDITNOTE.equals(trans.getDocumentCode())
 		) {
 			hasDueDate = false;
 		}