diff --git a/src/File/FileServer.py b/src/File/FileServer.py
index 599aaaae..5f1d9b47 100644
--- a/src/File/FileServer.py
+++ b/src/File/FileServer.py
@@ -150,6 +150,12 @@ class FileServer(ConnectionServer):
         FileRequest = imp.load_source("FileRequest", "src/File/FileRequest.py").FileRequest
 
     def portCheck(self):
+        if config.offline:
+            self.log.info("Offline mode: port check disabled")
+            res = {"ipv4": None, "ipv6": None}
+            self.port_opened = res
+            return res
+
         if config.ip_external:
             for ip_external in config.ip_external:
                 SiteManager.peer_blacklist.append((ip_external, self.port))  # Add myself to peer blacklist