diff --git a/changelog/unreleased/patch-3971.md b/changelog/unreleased/patch-3971.md
new file mode 100644
index 0000000000..cc7664cefe
--- /dev/null
+++ b/changelog/unreleased/patch-3971.md
@@ -0,0 +1,5 @@
+Bugfix: Fix for #3971
+
+Fixed panic described in #3971
+
+https://github.com/cs3org/reva/pull/3972
diff --git a/pkg/ocm/share/repository/nextcloud/nextcloud.go b/pkg/ocm/share/repository/nextcloud/nextcloud.go
index 775f370a47..76825d99e5 100644
--- a/pkg/ocm/share/repository/nextcloud/nextcloud.go
+++ b/pkg/ocm/share/repository/nextcloud/nextcloud.go
@@ -406,10 +406,10 @@ func (sm *Manager) UpdateReceivedShare(ctx context.Context, user *userpb.User, s
 }
 
 func getUsername(user *userpb.User) string {
-	if len(user.Username) > 0 {
+	if user != nil && len(user.Username) > 0 {
 		return user.Username
 	}
-	if len(user.Id.OpaqueId) > 0 {
+	if user != nil && len(user.Id.OpaqueId) > 0 {
 		return user.Id.OpaqueId
 	}