1 files changed, 5 insertions, 1 deletions
diff --git a/Lib/imaplib.py b/Lib/imaplib.py
index 0dfd852..e451413 100644
--- a/Lib/imaplib.py
+++ b/Lib/imaplib.py
@@ -282,7 +282,11 @@ class IMAP4:
 
 
     def _create_socket(self):
-        return socket.create_connection((self.host, self.port))
+        # Default value of IMAP4.host is '', but socket.getaddrinfo()
+        # (which is used by socket.create_connection()) expects None
+        # as a default value for host.
+        host = None if not self.host else self.host
+        return socket.create_connection((host, self.port))
 
     def open(self, host = '', port = IMAP4_PORT):
         """Setup connection to remote server on "host:port"