diff --git a/src/Listen.cxx b/src/Listen.cxx
index 3faccc954..987737f9f 100644
--- a/src/Listen.cxx
+++ b/src/Listen.cxx
@@ -24,6 +24,7 @@
 #include "config/ConfigGlobal.hxx"
 #include "config/ConfigOption.hxx"
 #include "net/SocketAddress.hxx"
+#include "net/UniqueSocketDescriptor.hxx"
 #include "event/ServerSocket.hxx"
 #include "system/Error.hxx"
 #include "util/RuntimeError.hxx"
@@ -50,7 +51,7 @@ public:
 		:ServerSocket(_loop), partition(_partition) {}
 
 private:
-	void OnAccept(UniqueSocketDescriptor &&fd,
+	void OnAccept(UniqueSocketDescriptor fd,
 		      SocketAddress address, int uid) override {
 		client_new(GetEventLoop(), partition,
 			   std::move(fd), address, uid);
diff --git a/src/client/Client.hxx b/src/client/Client.hxx
index 19ceb75c7..5efe45af5 100644
--- a/src/client/Client.hxx
+++ b/src/client/Client.hxx
@@ -97,7 +97,7 @@ public:
 	std::list<ClientMessage> messages;
 
 	Client(EventLoop &loop, Partition &partition,
-	       UniqueSocketDescriptor &&fd, int uid, int num);
+	       UniqueSocketDescriptor fd, int uid, int num);
 
 	~Client() {
 		if (FullyBufferedSocket::IsDefined())
@@ -239,7 +239,7 @@ client_manager_init();
 
 void
 client_new(EventLoop &loop, Partition &partition,
-	   UniqueSocketDescriptor &&fd, SocketAddress address, int uid);
+	   UniqueSocketDescriptor fd, SocketAddress address, int uid);
 
 /**
  * Write a printf-like formatted string to the client.
diff --git a/src/client/ClientNew.cxx b/src/client/ClientNew.cxx
index ce097e1df..5cfcf750f 100644
--- a/src/client/ClientNew.cxx
+++ b/src/client/ClientNew.cxx
@@ -42,7 +42,7 @@
 static constexpr char GREETING[] = "OK MPD " PROTOCOL_VERSION "\n";
 
 Client::Client(EventLoop &_loop, Partition &_partition,
-	       UniqueSocketDescriptor &&_fd, int _uid, int _num)
+	       UniqueSocketDescriptor _fd, int _uid, int _num)
 	:FullyBufferedSocket(_fd.Release(), _loop,
 			     16384, client_max_output_buffer_size),
 	 timeout_event(_loop, BIND_THIS_METHOD(OnTimeout)),
@@ -56,7 +56,7 @@ Client::Client(EventLoop &_loop, Partition &_partition,
 
 void
 client_new(EventLoop &loop, Partition &partition,
-	   UniqueSocketDescriptor &&fd, SocketAddress address, int uid)
+	   UniqueSocketDescriptor fd, SocketAddress address, int uid)
 {
 	static unsigned int next_client_num;
 	const auto remote = ToString(address);
diff --git a/src/event/ServerSocket.hxx b/src/event/ServerSocket.hxx
index 9e44143e3..7c69225b3 100644
--- a/src/event/ServerSocket.hxx
+++ b/src/event/ServerSocket.hxx
@@ -117,7 +117,7 @@ public:
 	void Close();
 
 protected:
-	virtual void OnAccept(UniqueSocketDescriptor &&fd,
+	virtual void OnAccept(UniqueSocketDescriptor fd,
 			      SocketAddress address, int uid) = 0;
 };
 
diff --git a/src/output/plugins/httpd/HttpdClient.cxx b/src/output/plugins/httpd/HttpdClient.cxx
index 7a55af198..4380b89ee 100644
--- a/src/output/plugins/httpd/HttpdClient.cxx
+++ b/src/output/plugins/httpd/HttpdClient.cxx
@@ -186,7 +186,7 @@ HttpdClient::SendResponse()
 	return true;
 }
 
-HttpdClient::HttpdClient(HttpdOutput &_httpd, UniqueSocketDescriptor &&_fd,
+HttpdClient::HttpdClient(HttpdOutput &_httpd, UniqueSocketDescriptor _fd,
 			 EventLoop &_loop,
 			 bool _metadata_supported)
 	:BufferedSocket(_fd.Release(), _loop),
diff --git a/src/output/plugins/httpd/HttpdClient.hxx b/src/output/plugins/httpd/HttpdClient.hxx
index 3c1049622..9a59de71a 100644
--- a/src/output/plugins/httpd/HttpdClient.hxx
+++ b/src/output/plugins/httpd/HttpdClient.hxx
@@ -132,7 +132,7 @@ public:
 	 * @param httpd the HTTP output device
 	 * @param _fd the socket file descriptor
 	 */
-	HttpdClient(HttpdOutput &httpd, UniqueSocketDescriptor &&_fd,
+	HttpdClient(HttpdOutput &httpd, UniqueSocketDescriptor _fd,
 		    EventLoop &_loop,
 		    bool _metadata_supported);
 
diff --git a/src/output/plugins/httpd/HttpdInternal.hxx b/src/output/plugins/httpd/HttpdInternal.hxx
index 5e6a39dbe..48e0aae2c 100644
--- a/src/output/plugins/httpd/HttpdInternal.hxx
+++ b/src/output/plugins/httpd/HttpdInternal.hxx
@@ -206,7 +206,7 @@ public:
 		return HasClients();
 	}
 
-	void AddClient(UniqueSocketDescriptor &&fd);
+	void AddClient(UniqueSocketDescriptor fd);
 
 	/**
 	 * Removes a client from the httpd_output.clients linked list.
@@ -257,7 +257,7 @@ public:
 private:
 	virtual void RunDeferred() override;
 
-	void OnAccept(UniqueSocketDescriptor &&fd,
+	void OnAccept(UniqueSocketDescriptor fd,
 		      SocketAddress address, int uid) override;
 };
 
diff --git a/src/output/plugins/httpd/HttpdOutputPlugin.cxx b/src/output/plugins/httpd/HttpdOutputPlugin.cxx
index 95e3edaab..526ef8ce6 100644
--- a/src/output/plugins/httpd/HttpdOutputPlugin.cxx
+++ b/src/output/plugins/httpd/HttpdOutputPlugin.cxx
@@ -118,7 +118,7 @@ HttpdOutput::Unbind()
  * HttpdOutput.clients linked list.
  */
 inline void
-HttpdOutput::AddClient(UniqueSocketDescriptor &&fd)
+HttpdOutput::AddClient(UniqueSocketDescriptor fd)
 {
 	auto *client = new HttpdClient(*this, std::move(fd), GetEventLoop(),
 				       !encoder->ImplementsTag());
@@ -151,7 +151,7 @@ HttpdOutput::RunDeferred()
 }
 
 void
-HttpdOutput::OnAccept(UniqueSocketDescriptor &&fd,
+HttpdOutput::OnAccept(UniqueSocketDescriptor fd,
 		      SocketAddress address, gcc_unused int uid)
 {
 	/* the listener socket has become readable - a client has