diff --git a/internal/http/services/owncloud/ocdav/copy.go b/internal/http/services/owncloud/ocdav/copy.go
index e078d323ef..a4905b1411 100644
--- a/internal/http/services/owncloud/ocdav/copy.go
+++ b/internal/http/services/owncloud/ocdav/copy.go
@@ -247,11 +247,17 @@ func (s *svc) executePathCopy(ctx context.Context, selector pool.Selectable[gate
 			Ref: cp.destination,
 			Opaque: &typespb.Opaque{
 				Map: map[string]*typespb.OpaqueEntry{
-					"Upload-Length": {
+					net.HeaderUploadLength: {
 						Decoder: "plain",
 						// TODO: handle case where size is not known in advance
 						Value: []byte(strconv.FormatUint(cp.sourceInfo.GetSize(), 10)),
 					},
+					net.HeaderOCMtime: {
+						Decoder: "plain",
+						Value: []byte(
+							utils.TimeToOCMtime(utils.TSToTime(cp.sourceInfo.GetMtime())),
+						),
+					},
 				},
 			},
 		}
@@ -461,6 +467,12 @@ func (s *svc) executeSpacesCopy(ctx context.Context, w http.ResponseWriter, sele
 						// TODO: handle case where size is not known in advance
 						Value: []byte(strconv.FormatUint(cp.sourceInfo.GetSize(), 10)),
 					},
+					net.HeaderOCMtime: {
+						Decoder: "plain",
+						Value: []byte(
+							utils.TimeToOCMtime(utils.TSToTime(cp.sourceInfo.GetMtime())),
+						),
+					},
 				},
 			},
 		}