diff --git a/src/libsync/owncloudpropagator_p.h b/src/libsync/owncloudpropagator_p.h
index 14e8f1721a..4fb0953428 100644
--- a/src/libsync/owncloudpropagator_p.h
+++ b/src/libsync/owncloudpropagator_p.h
@@ -52,11 +52,17 @@ inline QByteArray getEtagFromReply(QNetworkReply *reply)
 inline SyncFileItem::Status classifyError(QNetworkReply::NetworkError nerror, int httpCode) {
     Q_ASSERT (nerror != QNetworkReply::NoError); // we should only be called when there is an error
 
-    if (nerror > QNetworkReply::NoError &&  nerror <= QNetworkReply::UnknownProxyError) {
+    if (nerror > QNetworkReply::NoError && nerror <= QNetworkReply::UnknownProxyError) {
         // network error or proxy error -> fatal
         return SyncFileItem::FatalError;
     }
 
+    if (httpCode == 503) {
+        // "Service unavailable"
+        // Happens for maintenance mode and other temporary outages
+        return SyncFileItem::FatalError;
+    }
+
     if (httpCode == 412) {
         // "Precondition Failed"
         // Happens when the e-tag has changed