diff --git a/src/main/java/org/olat/core/commons/services/doceditor/onlyoffice/manager/OnlyOfficeServiceImpl.java b/src/main/java/org/olat/core/commons/services/doceditor/onlyoffice/manager/OnlyOfficeServiceImpl.java
index 66ac56f83b8638306413c3b9738e2eb0e2780426..dae9c6df7dfd1981432f42b4b560eca3506a97a8 100644
--- a/src/main/java/org/olat/core/commons/services/doceditor/onlyoffice/manager/OnlyOfficeServiceImpl.java
+++ b/src/main/java/org/olat/core/commons/services/doceditor/onlyoffice/manager/OnlyOfficeServiceImpl.java
@@ -206,7 +206,7 @@ public class OnlyOfficeServiceImpl implements OnlyOfficeService {
 	}
 
 	private String getDocumentKey(VFSMetadata metadata) {
-		String lastModified = LAST_MODIFIED.format(metadata.getLastModified());
+		String lastModified = LAST_MODIFIED.format(metadata.getFileLastModified());
 		return metadata.getUuid() + "-" + lastModified;
 	}