diff --git a/src/main/java/org/olat/upgrade/OLATUpgrade_13_0_0.java b/src/main/java/org/olat/upgrade/OLATUpgrade_13_0_0.java
index 50b89dd00529a01a367ca1725c3d1dd32e1656e3..4a706d8f29c5b933dd17792f2b7c43bdc7dab72f 100644
--- a/src/main/java/org/olat/upgrade/OLATUpgrade_13_0_0.java
+++ b/src/main/java/org/olat/upgrade/OLATUpgrade_13_0_0.java
@@ -238,7 +238,7 @@ public class OLATUpgrade_13_0_0 extends OLATUpgrade {
 			Long rollCallKey = auditLog.getRollCallKey();
 			if(rollCallKey != null) {
 				LectureBlockRollCall call = lectureService.getRollCall(new LectureBlockRollCallRefImpl(rollCallKey));
-				if(call.getAppealDate() == null) {
+				if(call != null && call.getAppealDate() == null) {
 					call.setAppealDate(auditLog.getCreationDate());
 					call.setAppealStatus(LectureBlockAppealStatus.oldWorkflow);
 					lectureService.updateRollCall(call);