diff --git a/endpoints.go b/endpoints.go
index 95f6fd9..b961908 100644
--- a/endpoints.go
+++ b/endpoints.go
@@ -136,7 +136,8 @@ var (
 
 	EndpointIntegrationsJoin = func(iID string) string { return EndpointAPI + "integrations/" + iID + "/join" }
 
-	EndpointEmoji = func(eID string) string { return EndpointAPI + "emojis/" + eID + ".png" }
+	EndpointEmoji         = func(eID string) string { return EndpointAPI + "emojis/" + eID + ".png" }
+	EndpointEmojiAnimated = func(eID string) string { return EndpointAPI + "emojis/" + eID + ".gif" }
 
 	EndpointOauth2          = EndpointAPI + "oauth2/"
 	EndpointApplications    = EndpointOauth2 + "applications"
diff --git a/eventhandlers.go b/eventhandlers.go
index 5cc157d..d2b9a98 100644
--- a/eventhandlers.go
+++ b/eventhandlers.go
@@ -50,6 +50,7 @@ const (
 	userUpdateEventType               = "USER_UPDATE"
 	voiceServerUpdateEventType        = "VOICE_SERVER_UPDATE"
 	voiceStateUpdateEventType         = "VOICE_STATE_UPDATE"
+	webhooksUpdateEventType           = "WEBHOOKS_UPDATE"
 )
 
 // channelCreateEventHandler is an event handler for ChannelCreate events.
@@ -892,6 +893,26 @@ func (eh voiceStateUpdateEventHandler) Handle(s *Session, i interface{}) {
 	}
 }
 
+// webhooksUpdateEventHandler is an event handler for WebhooksUpdate events.
+type webhooksUpdateEventHandler func(*Session, *WebhooksUpdate)
+
+// Type returns the event type for WebhooksUpdate events.
+func (eh webhooksUpdateEventHandler) Type() string {
+	return webhooksUpdateEventType
+}
+
+// New returns a new instance of WebhooksUpdate.
+func (eh webhooksUpdateEventHandler) New() interface{} {
+	return &WebhooksUpdate{}
+}
+
+// Handle is the handler for WebhooksUpdate events.
+func (eh webhooksUpdateEventHandler) Handle(s *Session, i interface{}) {
+	if t, ok := i.(*WebhooksUpdate); ok {
+		eh(s, t)
+	}
+}
+
 func handlerForInterface(handler interface{}) EventHandler {
 	switch v := handler.(type) {
 	case func(*Session, interface{}):
@@ -982,6 +1003,8 @@ func handlerForInterface(handler interface{}) EventHandler {
 		return voiceServerUpdateEventHandler(v)
 	case func(*Session, *VoiceStateUpdate):
 		return voiceStateUpdateEventHandler(v)
+	case func(*Session, *WebhooksUpdate):
+		return webhooksUpdateEventHandler(v)
 	}
 
 	return nil
@@ -1027,4 +1050,5 @@ func init() {
 	registerInterfaceProvider(userUpdateEventHandler(nil))
 	registerInterfaceProvider(voiceServerUpdateEventHandler(nil))
 	registerInterfaceProvider(voiceStateUpdateEventHandler(nil))
+	registerInterfaceProvider(webhooksUpdateEventHandler(nil))
 }
diff --git a/events.go b/events.go
index e784cac..c4fb520 100644
--- a/events.go
+++ b/events.go
@@ -254,3 +254,9 @@ type MessageDeleteBulk struct {
 	ChannelID string   `json:"channel_id"`
 	GuildID   string   `json:"guild_id"`
 }
+
+// WebhooksUpdate is the data for a WebhooksUpdate event
+type WebhooksUpdate struct {
+	GuildID   string `json:"guild_id"`
+	ChannelID string `json:"channel_id"`
+}
diff --git a/message_test.go b/message_test.go
index 8bff87b..792bfc4 100644
--- a/message_test.go
+++ b/message_test.go
@@ -12,7 +12,6 @@ func TestContentWithMoreMentionsReplaced(t *testing.T) {
 		Username: "User Name",
 	}
 
-	s.StateEnabled = true
 	s.State.GuildAdd(&Guild{ID: "guild"})
 	s.State.RoleAdd("guild", &Role{
 		ID:          "role",
diff --git a/restapi.go b/restapi.go
index 476f783..9d53065 100644
--- a/restapi.go
+++ b/restapi.go
@@ -90,7 +90,7 @@ func (s *Session) RequestWithLockedBucket(method, urlStr, contentType string, b
 
 	req.Header.Set("Content-Type", contentType)
 	// TODO: Make a configurable static variable.
-	req.Header.Set("User-Agent", fmt.Sprintf("DiscordBot (https://github.com/bwmarrin/discordgo, v%s)", VERSION))
+	req.Header.Set("User-Agent", "DiscordBot (https://github.com/bwmarrin/discordgo, v"+VERSION+")")
 
 	if s.Debug {
 		for k, v := range req.Header {
@@ -250,7 +250,7 @@ func (s *Session) Register(username string) (token string, err error) {
 // even use.
 func (s *Session) Logout() (err error) {
 
-	//  _, err = s.Request("POST", LOGOUT, fmt.Sprintf(`{"token": "%s"}`, s.Token))
+	//  _, err = s.Request("POST", LOGOUT, `{"token": "` + s.Token + `"}`)
 
 	if s.Token == "" {
 		return
@@ -428,7 +428,7 @@ func (s *Session) UserGuilds(limit int, beforeID, afterID string) (st []*UserGui
 	uri := EndpointUserGuilds("@me")
 
 	if len(v) > 0 {
-		uri = fmt.Sprintf("%s?%s", uri, v.Encode())
+		uri += "?" + v.Encode()
 	}
 
 	body, err := s.RequestWithBucketID("GET", uri, nil, EndpointUserGuilds(""))
@@ -743,7 +743,7 @@ func (s *Session) GuildMembers(guildID string, after string, limit int) (st []*M
 	}
 
 	if len(v) > 0 {
-		uri = fmt.Sprintf("%s?%s", uri, v.Encode())
+		uri += "?" + v.Encode()
 	}
 
 	body, err := s.RequestWithBucketID("GET", uri, nil, EndpointGuildMembers(guildID))
@@ -1065,7 +1065,7 @@ func (s *Session) GuildPruneCount(guildID string, days uint32) (count uint32, er
 		Pruned uint32 `json:"pruned"`
 	}{}
 
-	uri := EndpointGuildPrune(guildID) + fmt.Sprintf("?days=%d", days)
+	uri := EndpointGuildPrune(guildID) + "?days=" + strconv.FormatUint(uint64(days), 10)
 	body, err := s.RequestWithBucketID("GET", uri, nil, EndpointGuildPrune(guildID))
 	if err != nil {
 		return
@@ -1423,7 +1423,7 @@ func (s *Session) ChannelMessages(channelID string, limit int, beforeID, afterID
 		v.Set("around", aroundID)
 	}
 	if len(v) > 0 {
-		uri = fmt.Sprintf("%s?%s", uri, v.Encode())
+		uri += "?" + v.Encode()
 	}
 
 	body, err := s.RequestWithBucketID("GET", uri, nil, EndpointChannelMessages(channelID))
@@ -2103,7 +2103,7 @@ func (s *Session) MessageReactions(channelID, messageID, emojiID string, limit i
 	}
 
 	if len(v) > 0 {
-		uri = fmt.Sprintf("%s?%s", uri, v.Encode())
+		uri += "?" + v.Encode()
 	}
 
 	body, err := s.RequestWithBucketID("GET", uri, nil, EndpointMessageReaction(channelID, "", "", ""))
diff --git a/structs.go b/structs.go
index d089b5f..97f726c 100644
--- a/structs.go
+++ b/structs.go
@@ -597,7 +597,7 @@ type Member struct {
 	GuildID string `json:"guild_id"`
 
 	// The time at which the member joined the guild, in ISO8601.
-	JoinedAt string `json:"joined_at"`
+	JoinedAt Timestamp `json:"joined_at"`
 
 	// The nickname of the member, if they have one.
 	Nick string `json:"nick"`
@@ -615,6 +615,11 @@ type Member struct {
 	Roles []string `json:"roles"`
 }
 
+// Mention creates a member mention
+func (m *Member) Mention() string {
+	return "<@!" + m.User.ID + ">"
+}
+
 // A Settings stores data for a specific users Discord client settings.
 type Settings struct {
 	RenderEmbeds           bool               `json:"render_embeds"`
@@ -929,6 +934,7 @@ const (
 	ErrCodeUnknownToken       = 10012
 	ErrCodeUnknownUser        = 10013
 	ErrCodeUnknownEmoji       = 10014
+	ErrCodeUnknownWebhook     = 10015
 
 	ErrCodeBotsCannotUseEndpoint  = 20001
 	ErrCodeOnlyBotsCanUseEndpoint = 20002
diff --git a/types.go b/types.go
index 780b6bb..c0ce013 100644
--- a/types.go
+++ b/types.go
@@ -11,7 +11,6 @@ package discordgo
 
 import (
 	"encoding/json"
-	"fmt"
 	"net/http"
 	"time"
 )
@@ -54,5 +53,5 @@ func newRestError(req *http.Request, resp *http.Response, body []byte) *RESTErro
 }
 
 func (r RESTError) Error() string {
-	return fmt.Sprintf("HTTP %s, %s", r.Response.Status, r.ResponseBody)
+	return "HTTP " + r.Response.Status + ", " + string(r.ResponseBody)
 }
diff --git a/user.go b/user.go
index 618a7d5..a9af31a 100644
--- a/user.go
+++ b/user.go
@@ -1,9 +1,6 @@
 package discordgo
 
-import (
-	"fmt"
-	"strings"
-)
+import "strings"
 
 // A User stores all data for an individual Discord user.
 type User struct {
@@ -43,12 +40,12 @@ type User struct {
 
 // String returns a unique identifier of the form username#discriminator
 func (u *User) String() string {
-	return fmt.Sprintf("%s#%s", u.Username, u.Discriminator)
+	return u.Username + "#" + u.Discriminator
 }
 
 // Mention return a string which mentions the user
 func (u *User) Mention() string {
-	return fmt.Sprintf("<@%s>", u.ID)
+	return "<@" + u.ID + ">"
 }
 
 // AvatarURL returns a URL to the user's avatar.
diff --git a/voice.go b/voice.go
index 85fb6b8..b904508 100644
--- a/voice.go
+++ b/voice.go
@@ -14,6 +14,7 @@ import (
 	"encoding/json"
 	"fmt"
 	"net"
+	"strconv"
 	"strings"
 	"sync"
 	"time"
@@ -135,7 +136,6 @@ func (v *VoiceConnection) ChangeChannel(channelID string, mute, deaf bool) (err
 
 // Disconnect disconnects from this voice channel and closes the websocket
 // and udp connections to Discord.
-// !!! NOTE !!! this function may be removed in favour of ChannelVoiceLeave
 func (v *VoiceConnection) Disconnect() (err error) {
 
 	// Send a OP4 with a nil channel to disconnect
@@ -299,7 +299,7 @@ func (v *VoiceConnection) open() (err error) {
 	}
 
 	// Connect to VoiceConnection Websocket
-	vg := fmt.Sprintf("wss://%s", strings.TrimSuffix(v.endpoint, ":80"))
+	vg := "wss://" + strings.TrimSuffix(v.endpoint, ":80")
 	v.log(LogInformational, "connecting to voice endpoint %s", vg)
 	v.wsConn, _, err = websocket.DefaultDialer.Dial(vg, nil)
 	if err != nil {
@@ -542,7 +542,7 @@ func (v *VoiceConnection) udpOpen() (err error) {
 		return fmt.Errorf("empty endpoint")
 	}
 
-	host := fmt.Sprintf("%s:%d", strings.TrimSuffix(v.endpoint, ":80"), v.op2.Port)
+	host := strings.TrimSuffix(v.endpoint, ":80") + ":" + strconv.Itoa(v.op2.Port)
 	addr, err := net.ResolveUDPAddr("udp", host)
 	if err != nil {
 		v.log(LogWarning, "error resolving udp host %s, %s", host, err)
diff --git a/wsapi.go b/wsapi.go
index 80e85ac..9b94b23 100644
--- a/wsapi.go
+++ b/wsapi.go
@@ -85,6 +85,10 @@ func (s *Session) Open() error {
 		s.wsConn = nil // Just to be safe.
 		return err
 	}
+	
+	s.wsConn.SetCloseHandler(func(code int, text string) error {
+		return nil
+	})
 
 	defer func() {
 		// because of this, all code below must set err to the error