diff --git a/webdav/file.go b/webdav/file.go
index c48a17e..3cd19ff 100644
--- a/webdav/file.go
+++ b/webdav/file.go
@@ -547,11 +547,11 @@
 	npos := f.pos
 	// TODO: How to handle offsets greater than the size of system int?
 	switch whence {
-	case os.SEEK_SET:
+	case io.SeekStart:
 		npos = int(offset)
-	case os.SEEK_CUR:
+	case io.SeekCurrent:
 		npos += int(offset)
-	case os.SEEK_END:
+	case io.SeekEnd:
 		npos = len(f.n.data) + int(offset)
 	default:
 		npos = -1