diff --git a/lib/private/Files/Storage/DAV.php b/lib/private/Files/Storage/DAV.php
index bd818bf33a2..568262d9817 100644
--- a/lib/private/Files/Storage/DAV.php
+++ b/lib/private/Files/Storage/DAV.php
@@ -587,7 +587,7 @@ class DAV extends Common {
 				return false;
 			}
 			return [
-				'mtime' => isset($response['{DAV:}getlastmodified']) ? strtotime($response['{DAV:}getlastmodified']) : false,
+				'mtime' => isset($response['{DAV:}getlastmodified']) ? strtotime($response['{DAV:}getlastmodified']) : null,
 				'size' => (int)isset($response['{DAV:}getcontentlength']) ? $response['{DAV:}getcontentlength'] : 0,
 			];
 		} catch (\Exception $e) {