diff --git a/integrationtests/self/handshake_test.go b/integrationtests/self/handshake_test.go
index b17104c9..44b508ad 100644
--- a/integrationtests/self/handshake_test.go
+++ b/integrationtests/self/handshake_test.go
@@ -20,13 +20,16 @@ var _ = Describe("Handshake tests", func() {
 	)
 
 	BeforeEach(func() {
+		server = nil
 		acceptStopped = make(chan struct{})
 		serverConfig = &quic.Config{}
 	})
 
 	AfterEach(func() {
-		Expect(server.Close()).To(Succeed())
-		<-acceptStopped
+		if server != nil {
+			server.Close()
+			<-acceptStopped
+		}
 	})
 
 	runServer := func() {
@@ -60,7 +63,7 @@ var _ = Describe("Handshake tests", func() {
 			Expect(err).ToNot(HaveOccurred())
 		})
 
-		It("when the client supports more versions than the supports", func() {
+		It("when the client supports more versions than the server supports", func() {
 			if len(protocol.SupportedVersions) == 1 {
 				Skip("Test requires at least 2 supported versions.")
 			}
diff --git a/server.go b/server.go
index 03766f3e..e7ddae8f 100644
--- a/server.go
+++ b/server.go
@@ -40,15 +40,17 @@ type server struct {
 	certChain crypto.CertChain
 	scfg      *handshake.ServerConfig
 
-	sessions                  map[protocol.ConnectionID]packetHandler
-	sessionsMutex             sync.RWMutex
-	deleteClosedSessionsAfter time.Duration
+	sessionsMutex sync.RWMutex
+	sessions      map[protocol.ConnectionID]packetHandler
+	closed        bool
 
 	serverError  error
 	sessionQueue chan Session
 	errorChan    chan struct{}
 
-	newSession func(conn connection, v protocol.VersionNumber, connectionID protocol.ConnectionID, sCfg *handshake.ServerConfig, tlsConf *tls.Config, config *Config) (packetHandler, error)
+	// set as members, so they can be set in the tests
+	newSession                func(conn connection, v protocol.VersionNumber, connectionID protocol.ConnectionID, sCfg *handshake.ServerConfig, tlsConf *tls.Config, config *Config) (packetHandler, error)
+	deleteClosedSessionsAfter time.Duration
 }
 
 var _ Listener = &server{}
@@ -240,6 +242,12 @@ func (s *server) Accept() (Session, error) {
 // Close the server
 func (s *server) Close() error {
 	s.sessionsMutex.Lock()
+	if s.closed {
+		s.sessionsMutex.Unlock()
+		return nil
+	}
+	s.closed = true
+
 	var wg sync.WaitGroup
 	for _, session := range s.sessions {
 		if session != nil {
@@ -254,10 +262,9 @@ func (s *server) Close() error {
 	s.sessionsMutex.Unlock()
 	wg.Wait()
 
-	if s.conn == nil {
-		return nil
-	}
-	return s.conn.Close()
+	err := s.conn.Close()
+	<-s.errorChan // wait for serve() to return
+	return err
 }
 
 // Addr returns the server's network address
diff --git a/server_test.go b/server_test.go
index b82a14e4..1ca7e652 100644
--- a/server_test.go
+++ b/server_test.go
@@ -222,6 +222,7 @@ var _ = Describe("Server", func() {
 		})
 
 		It("closes sessions and the connection when Close is called", func() {
+			go serv.serve()
 			session, _ := newMockSession(nil, 0, 0, nil, nil, nil)
 			serv.sessions[1] = session
 			err := serv.Close()