diff --git a/main.py b/main.py
index a5bc75f..a60e395 100644
--- a/main.py
+++ b/main.py
@@ -42,7 +42,7 @@ class SeafileUploader():
         drop.clear()
         drop.setEnabled(False)
         select = 0
-        if self.seaf_client:
+        if self.seaf_client and self.seaf_client.ping():
             self.libs = (self.seaf_client or self.seaf_lib.client).libraries()
             i=0
             for lib in self.libs: