diff --git a/client.go b/client.go
index 6234a64c5..fc6ed290e 100644
--- a/client.go
+++ b/client.go
@@ -89,6 +89,7 @@ func DialAddrContext(
 // The same PacketConn can be used for multiple calls to Dial and Listen,
 // QUIC connection IDs are used for demultiplexing the different connections.
 // The host parameter is used for SNI.
+// The tls.Config must define an application protocol (using NextProtos).
 func Dial(
 	pconn net.PacketConn,
 	remoteAddr net.Addr,
@@ -121,8 +122,8 @@ func dialContext(
 	config *Config,
 	createdPacketConn bool,
 ) (Session, error) {
-	if tlsConf == nil || len(tlsConf.NextProtos) == 0 {
-		return nil, errors.New("quic: NextProtos not set in tls.Config")
+	if tlsConf == nil {
+		return nil, errors.New("quic: tls.Config not set")
 	}
 	config = populateClientConfig(config, createdPacketConn)
 	packetHandlers, err := getMultiplexer().AddConn(pconn, config.ConnectionIDLength, config.StatelessResetKey)
diff --git a/client_test.go b/client_test.go
index 60965e69c..8c4cfcbde 100644
--- a/client_test.go
+++ b/client_test.go
@@ -463,11 +463,6 @@ var _ = Describe("Client", func() {
 				Expect(err).To(MatchError("0x1234 is not a valid QUIC version"))
 			})
 
-			It("erros when the tls.Config doesn't contain NextProtos", func() {
-				_, err := Dial(packetConn, nil, "localhost:1234", &tls.Config{}, nil)
-				Expect(err).To(MatchError("quic: NextProtos not set in tls.Config"))
-			})
-
 			It("disables bidirectional streams", func() {
 				config := &Config{
 					MaxIncomingStreams:    -1,
diff --git a/server.go b/server.go
index 2c7c451f0..5a267b36c 100644
--- a/server.go
+++ b/server.go
@@ -128,10 +128,11 @@ func ListenAddr(addr string, tlsConf *tls.Config, config *Config) (Listener, err
 }
 
 // Listen listens for QUIC connections on a given net.PacketConn.
-// A single PacketConn only be used for a single call to Listen.
+// A single net.PacketConn only be used for a single call to Listen.
 // The PacketConn can be used for simultaneous calls to Dial.
 // QUIC connection IDs are used for demultiplexing the different connections.
 // The tls.Config must not be nil and must contain a certificate configuration.
+// Furthermore, it must define an application control (using NextProtos).
 // The quic.Config may be nil, in that case the default values will be used.
 func Listen(conn net.PacketConn, tlsConf *tls.Config, config *Config) (Listener, error) {
 	return listen(conn, tlsConf, config)
@@ -139,11 +140,8 @@ func Listen(conn net.PacketConn, tlsConf *tls.Config, config *Config) (Listener,
 
 func listen(conn net.PacketConn, tlsConf *tls.Config, config *Config) (*server, error) {
 	// TODO(#1655): only require that tls.Config.Certificates or tls.Config.GetCertificate is set
-	if tlsConf == nil || len(tlsConf.Certificates) == 0 {
-		return nil, errors.New("quic: Certificates not set in tls.Config")
-	}
-	if len(tlsConf.NextProtos) == 0 {
-		return nil, errors.New("quic: NextProtos not set in tls.Config")
+	if tlsConf == nil {
+		return nil, errors.New("quic: tls.Config not set")
 	}
 	config = populateServerConfig(config)
 	for _, v := range config.Versions {
diff --git a/server_test.go b/server_test.go
index 0a966688d..caa5935b9 100644
--- a/server_test.go
+++ b/server_test.go
@@ -49,20 +49,7 @@ var _ = Describe("Server", func() {
 	It("errors when no tls.Config is given", func() {
 		_, err := ListenAddr("localhost:0", nil, nil)
 		Expect(err).To(HaveOccurred())
-		Expect(err.Error()).To(ContainSubstring("quic: Certificates not set in tls.Config"))
-	})
-
-	It("errors when no certificates are set in the tls.Config is given", func() {
-		_, err := ListenAddr("localhost:0", &tls.Config{}, nil)
-		Expect(err).To(HaveOccurred())
-		Expect(err.Error()).To(ContainSubstring("quic: Certificates not set in tls.Config"))
-	})
-
-	It("errors when NextProtos is not set in the tls.Config", func() {
-		tlsConf.NextProtos = nil
-		_, err := ListenAddr("localhost:0", tlsConf, nil)
-		Expect(err).To(HaveOccurred())
-		Expect(err.Error()).To(ContainSubstring("quic: NextProtos not set in tls.Config"))
+		Expect(err.Error()).To(ContainSubstring("quic: tls.Config not set"))
 	})
 
 	It("errors when the Config contains an invalid version", func() {