diff --git a/builtin.go b/builtin.go
index 05fe8fd..fafa2a6 100644
--- a/builtin.go
+++ b/builtin.go
@@ -143,13 +143,13 @@ func handleJOIN(c *Client, e Event) {
 		channel = c.state.lookupChannel(channelName)
 	}
 
-	user := c.state.lookupUser(e.Source.ID)
+	user := c.state.lookupUser(e.Source.ID())
 	if user == nil {
 		if ok := c.state.createUser(e.Source); !ok {
 			c.state.Unlock()
 			return
 		}
-		user = c.state.lookupUser(e.Source.ID)
+		user = c.state.lookupUser(e.Source.ID())
 	}
 
 	defer c.state.notify(c, UPDATE_STATE)
@@ -169,7 +169,7 @@ func handleJOIN(c *Client, e Event) {
 	}
 	c.state.Unlock()
 
-	if e.Source.ID == ToRFC1459(c.GetNick()) {
+	if e.Source.ID() == ToRFC1459(c.GetNick()) {
 		// If it's us, don't just add our user to the list. Run a WHO which
 		// will tell us who exactly is in the entire channel.
 		c.Send(&Event{Command: WHO, Params: []string{channelName, "%tacuhnr,1"}})
@@ -209,7 +209,7 @@ func handlePART(c *Client, e Event) {
 
 	defer c.state.notify(c, UPDATE_STATE)
 
-	if e.Source.ID == ToRFC1459(c.GetNick()) {
+	if e.Source.ID() == ToRFC1459(c.GetNick()) {
 		c.state.Lock()
 		c.state.deleteChannel(channel)
 		c.state.Unlock()
@@ -217,7 +217,7 @@ func handlePART(c *Client, e Event) {
 	}
 
 	c.state.Lock()
-	c.state.deleteUser(channel, e.Source.ID)
+	c.state.deleteUser(channel, e.Source.ID())
 	c.state.Unlock()
 }
 
@@ -327,9 +327,9 @@ func handleNICK(c *Client, e Event) {
 	c.state.Lock()
 	// renameUser updates the LastActive time automatically.
 	if len(e.Params) == 1 {
-		c.state.renameUser(e.Source.ID, e.Params[0])
+		c.state.renameUser(e.Source.ID(), e.Params[0])
 	} else if len(e.Trailing) > 0 {
-		c.state.renameUser(e.Source.ID, e.Trailing)
+		c.state.renameUser(e.Source.ID(), e.Trailing)
 	}
 	c.state.Unlock()
 	c.state.notify(c, UPDATE_STATE)
@@ -341,12 +341,12 @@ func handleQUIT(c *Client, e Event) {
 		return
 	}
 
-	if e.Source.ID == ToRFC1459(c.GetNick()) {
+	if e.Source.ID() == ToRFC1459(c.GetNick()) {
 		return
 	}
 
 	c.state.Lock()
-	c.state.deleteUser("", e.Source.ID)
+	c.state.deleteUser("", e.Source.ID())
 	c.state.Unlock()
 	c.state.notify(c, UPDATE_STATE)
 }
@@ -464,22 +464,21 @@ func handleNAMES(c *Client, e Event) {
 		} else {
 			s = &Source{
 				Name: nick,
-				ID:   ToRFC1459(nick),
 			}
 
-			if !IsValidNick(s.ID) {
+			if !IsValidNick(s.Name) {
 				continue
 			}
 		}
 
 		c.state.createUser(s)
-		user := c.state.lookupUser(s.ID)
+		user := c.state.lookupUser(s.ID())
 		if user == nil {
 			continue
 		}
 
 		user.addChannel(channel.Name)
-		channel.addUser(s.ID)
+		channel.addUser(s.ID())
 
 		// Don't append modes, overwrite them.
 		perms, _ := user.Perms.Lookup(channel.Name)
@@ -502,7 +501,7 @@ func updateLastActive(c *Client, e Event) {
 	c.state.Lock()
 
 	// Update the users last active time, if they exist.
-	user := c.state.lookupUser(e.Source.ID)
+	user := c.state.lookupUser(e.Source.ID())
 	if user == nil {
 		c.state.Unlock()
 		return
diff --git a/cap.go b/cap.go
index 11ac3a3..e627eec 100644
--- a/cap.go
+++ b/cap.go
@@ -193,7 +193,7 @@ func handleCHGHOST(c *Client, e Event) {
 	}
 
 	c.state.Lock()
-	user := c.state.lookupUser(e.Source.ID)
+	user := c.state.lookupUser(e.Source.ID())
 	if user != nil {
 		user.Ident = e.Params[0]
 		user.Host = e.Params[1]
@@ -206,7 +206,7 @@ func handleCHGHOST(c *Client, e Event) {
 // when users are no longer away, or when they are away.
 func handleAWAY(c *Client, e Event) {
 	c.state.Lock()
-	user := c.state.lookupUser(e.Source.ID)
+	user := c.state.lookupUser(e.Source.ID())
 	if user != nil {
 		user.Extras.Away = e.Trailing
 	}
@@ -229,7 +229,7 @@ func handleACCOUNT(c *Client, e Event) {
 	}
 
 	c.state.Lock()
-	user := c.state.lookupUser(e.Source.ID)
+	user := c.state.lookupUser(e.Source.ID())
 	if user != nil {
 		user.Extras.Account = account
 	}
diff --git a/cap_tags.go b/cap_tags.go
index 85e6a0b..aff10f6 100644
--- a/cap_tags.go
+++ b/cap_tags.go
@@ -25,7 +25,7 @@ func handleTags(c *Client, e Event) {
 	}
 
 	c.state.Lock()
-	user := c.state.lookupUser(e.Source.ID)
+	user := c.state.lookupUser(e.Source.ID())
 	if user != nil {
 		user.Extras.Account = account
 	}
diff --git a/conn.go b/conn.go
index c778bb5..9fe6103 100644
--- a/conn.go
+++ b/conn.go
@@ -374,7 +374,7 @@ func (c *Client) readLoop(ctx context.Context, errs chan error, wg *sync.WaitGro
 			// Check if it's an echo-message.
 			if !c.Config.disableTracking {
 				event.Echo = (event.Command == PRIVMSG || event.Command == NOTICE) &&
-					event.Source != nil && event.Source.ID == ToRFC1459(c.GetNick())
+					event.Source != nil && event.Source.ID() == ToRFC1459(c.GetNick())
 			}
 
 			c.rx <- event
diff --git a/ctcp.go b/ctcp.go
index 48b165d..56f4c85 100644
--- a/ctcp.go
+++ b/ctcp.go
@@ -155,8 +155,8 @@ func (c *CTCP) call(client *Client, event *CTCPEvent) {
 		}
 
 		// Send a ERRMSG reply, if we know who sent it.
-		if event.Source != nil && IsValidNick(event.Source.ID) {
-			client.Cmd.SendCTCPReply(event.Source.ID, CTCP_ERRMSG, "that is an unknown CTCP query")
+		if event.Source != nil && IsValidNick(event.Source.ID()) {
+			client.Cmd.SendCTCPReply(event.Source.ID(), CTCP_ERRMSG, "that is an unknown CTCP query")
 		}
 		return
 	}
@@ -248,7 +248,7 @@ func handleCTCPPing(client *Client, ctcp CTCPEvent) {
 	if ctcp.Reply {
 		return
 	}
-	client.Cmd.SendCTCPReply(ctcp.Source.ID, CTCP_PING, ctcp.Text)
+	client.Cmd.SendCTCPReply(ctcp.Source.ID(), CTCP_PING, ctcp.Text)
 }
 
 // handleCTCPPong replies with a pong.
@@ -256,7 +256,7 @@ func handleCTCPPong(client *Client, ctcp CTCPEvent) {
 	if ctcp.Reply {
 		return
 	}
-	client.Cmd.SendCTCPReply(ctcp.Source.ID, CTCP_PONG, "")
+	client.Cmd.SendCTCPReply(ctcp.Source.ID(), CTCP_PONG, "")
 }
 
 // handleCTCPVersion replies with the name of the client, Go version, as well
@@ -264,12 +264,12 @@ func handleCTCPPong(client *Client, ctcp CTCPEvent) {
 // arm, etc).
 func handleCTCPVersion(client *Client, ctcp CTCPEvent) {
 	if client.Config.Version != "" {
-		client.Cmd.SendCTCPReply(ctcp.Source.ID, CTCP_VERSION, client.Config.Version)
+		client.Cmd.SendCTCPReply(ctcp.Source.ID(), CTCP_VERSION, client.Config.Version)
 		return
 	}
 
 	client.Cmd.SendCTCPReplyf(
-		ctcp.Source.ID, CTCP_VERSION,
+		ctcp.Source.ID(), CTCP_VERSION,
 		"girc (github.com/lrstanley/girc) using %s (%s, %s)",
 		runtime.Version(), runtime.GOOS, runtime.GOARCH,
 	)
@@ -277,13 +277,13 @@ func handleCTCPVersion(client *Client, ctcp CTCPEvent) {
 
 // handleCTCPSource replies with the public git location of this library.
 func handleCTCPSource(client *Client, ctcp CTCPEvent) {
-	client.Cmd.SendCTCPReply(ctcp.Source.ID, CTCP_SOURCE, "https://github.com/lrstanley/girc")
+	client.Cmd.SendCTCPReply(ctcp.Source.ID(), CTCP_SOURCE, "https://github.com/lrstanley/girc")
 }
 
 // handleCTCPTime replies with a RFC 1123 (Z) formatted version of Go's
 // local time.
 func handleCTCPTime(client *Client, ctcp CTCPEvent) {
-	client.Cmd.SendCTCPReply(ctcp.Source.ID, CTCP_TIME, ":"+time.Now().Format(time.RFC1123Z))
+	client.Cmd.SendCTCPReply(ctcp.Source.ID(), CTCP_TIME, ":"+time.Now().Format(time.RFC1123Z))
 }
 
 // handleCTCPFinger replies with the realname and idle time of the user. This
@@ -293,5 +293,5 @@ func handleCTCPFinger(client *Client, ctcp CTCPEvent) {
 	active := client.conn.lastActive
 	client.conn.mu.RUnlock()
 
-	client.Cmd.SendCTCPReply(ctcp.Source.ID, CTCP_FINGER, fmt.Sprintf("%s -- idle %s", client.Config.Name, time.Since(active)))
+	client.Cmd.SendCTCPReply(ctcp.Source.ID(), CTCP_FINGER, fmt.Sprintf("%s -- idle %s", client.Config.Name, time.Since(active)))
 }
diff --git a/event.go b/event.go
index 3cca0eb..69f8214 100644
--- a/event.go
+++ b/event.go
@@ -516,9 +516,6 @@ const (
 // Source represents the sender of an IRC event, see RFC1459 section 2.3.1.
 // <servername> | <nick> [ '!' <user> ] [ '@' <host> ]
 type Source struct {
-	// ID is the nickname, server name, or service name, in it's converted
-	// and comparable) form.
-	ID string `json:"id"`
 	// Name is the nickname, server name, or service name, in its original
 	// non-rfc1459 form.
 	Name string `json:"name"`
@@ -529,6 +526,12 @@ type Source struct {
 	Host string `json:"host"`
 }
 
+// ID is the nickname, server name, or service name, in it's converted
+// and comparable) form.
+func (s *Source) ID() string {
+	return ToRFC1459(s.Name)
+}
+
 // Equals compares two Sources for equality.
 func (s *Source) Equals(ss *Source) bool {
 	if s == nil && ss == nil {
@@ -537,7 +540,7 @@ func (s *Source) Equals(ss *Source) bool {
 	if s != nil && ss == nil || s == nil && ss != nil {
 		return false
 	}
-	if s.ID != ss.ID || s.Ident != ss.Ident || s.Host != ss.Host {
+	if s.ID() != ss.ID() || s.Ident != ss.Ident || s.Host != ss.Host {
 		return false
 	}
 	return true
@@ -550,7 +553,6 @@ func (s *Source) Copy() *Source {
 	}
 
 	newSource := &Source{
-		ID:    s.ID,
 		Name:  s.Name,
 		Ident: s.Ident,
 		Host:  s.Host,
@@ -581,8 +583,6 @@ func ParseSource(raw string) (src *Source) {
 		src.Name = raw
 	}
 
-	src.ID = ToRFC1459(src.Name)
-
 	return src
 }
 
diff --git a/event_test.go b/event_test.go
index 27e22b9..bea94e0 100644
--- a/event_test.go
+++ b/event_test.go
@@ -11,7 +11,7 @@ import (
 
 func mockEvent() *Event {
 	return &Event{
-		Source:   &Source{ID: "nick", Name: "nick", Ident: "user", Host: "host.com"},
+		Source:   &Source{Name: "nick", Ident: "user", Host: "host.com"},
 		Command:  "PRIVMSG",
 		Params:   []string{"#channel"},
 		Trailing: "1 2 3",
@@ -47,7 +47,6 @@ func TestParseSource(t *testing.T) {
 		}},
 	}
 	for _, tt := range tests {
-		tt.wantSrc.ID = ToRFC1459(tt.wantSrc.Name)
 		gotSrc := ParseSource(tt.args.raw)
 
 		if !reflect.DeepEqual(gotSrc, tt.wantSrc) {
diff --git a/state.go b/state.go
index d42c0f1..0660a68 100644
--- a/state.go
+++ b/state.go
@@ -420,12 +420,12 @@ func (s *state) lookupUser(name string) *User {
 
 // createUser creates the user in state, if not already done.
 func (s *state) createUser(src *Source) (ok bool) {
-	if _, ok := s.users[src.ID]; ok {
+	if _, ok := s.users[src.ID()]; ok {
 		// User already exists.
 		return false
 	}
 
-	s.users[src.ID] = &User{
+	s.users[src.ID()] = &User{
 		Nick:       src.Name,
 		Host:       src.Host,
 		Ident:      src.Ident,