diff --git a/library/src/main/java/org/mustangproject/ZUGFeRD/OXPullProvider.java b/library/src/main/java/org/mustangproject/ZUGFeRD/OXPullProvider.java
index 7347d422..eb3ff49c 100644
--- a/library/src/main/java/org/mustangproject/ZUGFeRD/OXPullProvider.java
+++ b/library/src/main/java/org/mustangproject/ZUGFeRD/OXPullProvider.java
@@ -32,6 +32,7 @@ import java.util.Map;
 
 import org.mustangproject.EStandard;
 import org.mustangproject.FileAttachment;
+import org.mustangproject.ReferencedDocument;
 import org.mustangproject.XMLTools;
 
 public class OXPullProvider extends ZUGFeRD2PullProvider {
@@ -460,7 +461,7 @@ public class OXPullProvider extends ZUGFeRD2PullProvider {
 			xml += "</ram:InvoiceReferencedDocument>";
 		}
 		if (trans.getInvoiceReferencedDocuments() != null) {
-			for (var doc : trans.getInvoiceReferencedDocuments()) {
+			for (ReferencedDocument doc : trans.getInvoiceReferencedDocuments()) {
 				xml += "<ram:InvoiceReferencedDocument>"
 						+ "<ram:IssuerAssignedID>"
 						+ XMLTools.encodeXML(doc.getIssuerAssignedID()) + "</ram:IssuerAssignedID>";
diff --git a/library/src/main/java/org/mustangproject/ZUGFeRD/ZUGFeRD2PullProvider.java b/library/src/main/java/org/mustangproject/ZUGFeRD/ZUGFeRD2PullProvider.java
index 79ea800e..9cbf6afa 100644
--- a/library/src/main/java/org/mustangproject/ZUGFeRD/ZUGFeRD2PullProvider.java
+++ b/library/src/main/java/org/mustangproject/ZUGFeRD/ZUGFeRD2PullProvider.java
@@ -45,6 +45,7 @@ import org.dom4j.io.OutputFormat;
 import org.dom4j.io.XMLWriter;
 import org.mustangproject.FileAttachment;
 import org.mustangproject.IncludedNote;
+import org.mustangproject.ReferencedDocument;
 import org.mustangproject.XMLTools;
 import org.mustangproject.ZUGFeRD.model.DocumentCodeTypeConstants;
 import org.slf4j.Logger;
@@ -898,7 +899,7 @@ public class ZUGFeRD2PullProvider implements IXMLProvider {
 			xml += "</ram:InvoiceReferencedDocument>";
 		}
 		if (trans.getInvoiceReferencedDocuments() != null) {
-			for (var doc : trans.getInvoiceReferencedDocuments()) {
+			for (ReferencedDocument doc : trans.getInvoiceReferencedDocuments()) {
 				xml += "<ram:InvoiceReferencedDocument>"
 						+ "<ram:IssuerAssignedID>"
 						+ XMLTools.encodeXML(doc.getIssuerAssignedID()) + "</ram:IssuerAssignedID>";