diff --git a/src/calibre/srv/loop.py b/src/calibre/srv/loop.py
index c284b8b7a4..dd17b90279 100644
--- a/src/calibre/srv/loop.py
+++ b/src/calibre/srv/loop.py
@@ -411,6 +411,7 @@ class ServerLoop:
             self.ssl_context.set_servername_callback(self.on_ssl_servername)
 
         self.pre_activated_socket = None
+        self.socket_was_preactivated = False
         if self.opts.allow_socket_preallocation:
             from calibre.srv.pre_activated import pre_activated_socket
             self.pre_activated_socket = pre_activated_socket()
@@ -501,12 +502,14 @@ class ServerLoop:
                 self.do_bind()
         else:
             self.socket = self.pre_activated_socket
+            self.socket_was_preactivated = True
             self.pre_activated_socket = None
             self.setup_socket()
 
     def serve(self):
         self.connection_map = {}
-        self.socket.listen(min(socket.SOMAXCONN, 128))
+        if not self.socket_was_preactivated:
+            self.socket.listen(min(socket.SOMAXCONN, 128))
         self.bound_address = ba = self.socket.getsockname()
         if isinstance(ba, tuple):
             ba = ':'.join(map(str, ba))
diff --git a/src/calibre/srv/tests/loop.py b/src/calibre/srv/tests/loop.py
index 13870cee1a..a5f3bccc01 100644
--- a/src/calibre/srv/tests/loop.py
+++ b/src/calibre/srv/tests/loop.py
@@ -214,6 +214,7 @@ class LoopTest(BaseTest):
         os.closerange(3, 4)  # Ensure the socket gets fileno == 3
         s = socket.socket(socket.AF_INET, socket.SOCK_STREAM, 0)
         s.bind(('localhost', 0))
+        s.listen()  # pre-activated sockets are already listening
         port = s.getsockname()[1]
         self.ae(s.fileno(), 3)
         os.environ['LISTEN_PID'] = str(os.getpid())