diff --git a/vorgang-manager-server/src/main/java/de/ozgcloud/vorgang/files/UploadServerStreamObserver.java b/vorgang-manager-server/src/main/java/de/ozgcloud/vorgang/files/UploadServerStreamObserver.java
index 9821a129bf1383698da976c85fc3d787d92c13d0..c5aae5ab3f60383fe2f696ffffc4cc85af08d796 100644
--- a/vorgang-manager-server/src/main/java/de/ozgcloud/vorgang/files/UploadServerStreamObserver.java
+++ b/vorgang-manager-server/src/main/java/de/ozgcloud/vorgang/files/UploadServerStreamObserver.java
@@ -85,8 +85,10 @@ class UploadServerStreamObserver<M, T> implements StreamObserver<T> {
 	@Override
 	public synchronized void onNext(T fileUploadRequest) {
 		if (hasMetadata.test(fileUploadRequest)) {
+			LOG.debug("Received metadata.");
 			setMetadata(fileUploadRequest);
 		} else {
+			LOG.debug("Received file content chunk.");
 			if (Objects.isNull(contentIdFuture)) {
 				contentIdFuture = initContentUpload();
 			}
@@ -139,6 +141,7 @@ class UploadServerStreamObserver<M, T> implements StreamObserver<T> {
 		LOG.debug("Complete upload request.");
 		closeOutputPipe();
 		var newContentId = getContentId();
+		LOG.debug("newContentId: {}", newContentId);
 		try {
 			var fileId = metadataUploader.apply(fileMetadata.get(), newContentId);
 			responseConsumer.accept(fileId);