diff --git a/gencapdefs.py b/gencapdefs.py
index a0dcd0f4..9c3fe2e3 100644
--- a/gencapdefs.py
+++ b/gencapdefs.py
@@ -123,6 +123,12 @@ CAPDEFS = [
         url="https://ircv3.net/specs/extensions/server-time-3.2.html",
         standard="IRCv3",
     ),
+    CapDef(
+        identifier="SetName",
+        name="draft/setname",
+        url="https://github.com/ircv3/ircv3-specifications/pull/361",
+        standard="proposed IRCv3",
+    ),
     CapDef(
         identifier="STS",
         name="sts",
diff --git a/irc/caps/defs.go b/irc/caps/defs.go
index 74ff1de6..adfbbb7d 100644
--- a/irc/caps/defs.go
+++ b/irc/caps/defs.go
@@ -7,7 +7,7 @@ package caps
 
 const (
 	// number of recognized capabilities:
-	numCapabs = 20
+	numCapabs = 21
 	// length of the uint64 array that represents the bitset:
 	bitsetLen = 1
 )
@@ -85,6 +85,10 @@ const (
 	// https://ircv3.net/specs/extensions/server-time-3.2.html
 	ServerTime Capability = iota
 
+	// SetName is the proposed IRCv3 capability named "draft/setname":
+	// https://github.com/ircv3/ircv3-specifications/pull/361
+	SetName Capability = iota
+
 	// STS is the IRCv3 capability named "sts":
 	// https://ircv3.net/specs/extensions/sts.html
 	STS Capability = iota
@@ -115,6 +119,7 @@ var (
 		"draft/resume-0.3",
 		"sasl",
 		"server-time",
+		"draft/setname",
 		"sts",
 		"userhost-in-names",
 	}
diff --git a/irc/commands.go b/irc/commands.go
index fce1b5df..92e1bfb2 100644
--- a/irc/commands.go
+++ b/irc/commands.go
@@ -252,6 +252,10 @@ func init() {
 			handler:   sceneHandler,
 			minParams: 2,
 		},
+		"SETNAME": {
+			handler:   setnameHandler,
+			minParams: 1,
+		},
 		"TAGMSG": {
 			handler:   tagmsgHandler,
 			minParams: 1,
diff --git a/irc/handlers.go b/irc/handlers.go
index e6210d03..64534610 100644
--- a/irc/handlers.go
+++ b/irc/handlers.go
@@ -2310,6 +2310,22 @@ func sceneHandler(server *Server, client *Client, msg ircmsg.IrcMessage, rb *Res
 	return false
 }
 
+// SETNAME <realname>
+func setnameHandler(server *Server, client *Client, msg ircmsg.IrcMessage, rb *ResponseBuffer) bool {
+	realname := msg.Params[0]
+
+	client.stateMutex.Lock()
+	client.realname = realname
+	client.stateMutex.Unlock()
+
+	// alert friends
+	for friend := range client.Friends(caps.SetName) {
+		friend.SendFromClient("", client, nil, "SETNAME", realname)
+	}
+
+	return false
+}
+
 // TAGMSG <target>{,<target>}
 func tagmsgHandler(server *Server, client *Client, msg ircmsg.IrcMessage, rb *ResponseBuffer) bool {
 	clientOnlyTags := utils.GetClientOnlyTags(msg.Tags)
diff --git a/irc/help.go b/irc/help.go
index cef0f1d0..e2a94e0f 100644
--- a/irc/help.go
+++ b/irc/help.go
@@ -434,6 +434,11 @@ opers. For more specific information on mode characters, see the help for
 		text: `SCENE <target> <text to be sent>
 
 The SCENE command is used to send a scene notification to the given target.`,
+	},
+	"setname": {
+		text: `SETNAME <realname>
+
+The SETNAME command updates the realname to be the newly-given one.`,
 	},
 	"tagmsg": {
 		text: `@+client-only-tags TAGMSG <target>{,<target>}
diff --git a/irc/server.go b/irc/server.go
index c478afdb..fdf4f01e 100644
--- a/irc/server.go
+++ b/irc/server.go
@@ -47,7 +47,7 @@ var (
 
 	// SupportedCapabilities are the caps we advertise.
 	// MaxLine, SASL and STS are set during server startup.
-	SupportedCapabilities = caps.NewSet(caps.AccountTag, caps.AccountNotify, caps.AwayNotify, caps.Batch, caps.CapNotify, caps.ChgHost, caps.EchoMessage, caps.ExtendedJoin, caps.InviteNotify, caps.LabeledResponse, caps.Languages, caps.MessageTags, caps.MultiPrefix, caps.Rename, caps.Resume, caps.ServerTime, caps.UserhostInNames)
+	SupportedCapabilities = caps.NewSet(caps.AccountTag, caps.AccountNotify, caps.AwayNotify, caps.Batch, caps.CapNotify, caps.ChgHost, caps.EchoMessage, caps.ExtendedJoin, caps.InviteNotify, caps.LabeledResponse, caps.Languages, caps.MessageTags, caps.MultiPrefix, caps.Rename, caps.Resume, caps.ServerTime, caps.SetName, caps.UserhostInNames)
 
 	// CapValues are the actual values we advertise to v3.2 clients.
 	// actual values are set during server startup.