diff --git a/internal/handlers/api.go b/internal/handlers/api.go
index 3d98775..cde58bd 100644
--- a/internal/handlers/api.go
+++ b/internal/handlers/api.go
@@ -1951,8 +1951,9 @@ func (hdlr *Handlers) handleQuit(
 		http.StatusOK)
 }
 
-// handleMode handles the MODE command for channels and
-// users. Currently supports query-only (no mode changes).
+// handleMode handles the MODE command: a target that starts
+// with # is a channel, handled by handleChannelMode, and any
+// other target a nick, handled by handleUserMode.
 func (hdlr *Handlers) handleMode(
 	writer http.ResponseWriter,
 	request *http.Request,
diff --git a/internal/handlers/utility.go b/internal/handlers/utility.go
index 0ae2242..30dcb02 100644
--- a/internal/handlers/utility.go
+++ b/internal/handlers/utility.go
@@ -106,22 +106,20 @@ func (hdlr *Handlers) handleAdmin(
 ) {
 	ctx := request.Context()
 	srvName := hdlr.serverName()
+	location1, location2, email := hdlr.svc.AdminLines(srvName)
 
 	hdlr.enqueueNumeric(
 		ctx, clientID, irc.RplAdminMe, nick,
 		[]string{srvName}, "Administrative info",
 	)
 	hdlr.enqueueNumeric(
-		ctx, clientID, irc.RplAdminLoc1, nick, nil,
-		"neoirc server",
+		ctx, clientID, irc.RplAdminLoc1, nick, nil, location1,
 	)
 	hdlr.enqueueNumeric(
-		ctx, clientID, irc.RplAdminLoc2, nick, nil,
-		"IRC over HTTP",
+		ctx, clientID, irc.RplAdminLoc2, nick, nil, location2,
 	)
 	hdlr.enqueueNumeric(
-		ctx, clientID, irc.RplAdminEmail, nick, nil,
-		"admin@"+srvName,
+		ctx, clientID, irc.RplAdminEmail, nick, nil, email,
 	)
 	hdlr.broker.Notify(sessionID)
 	hdlr.respondJSON(writer, request,
@@ -199,7 +197,7 @@ func (hdlr *Handlers) handleKill(
 		return
 	}
 
-	reason := "KILLed"
+	reason := ""
 	if len(lines) > 1 {
 		reason = lines[1]
 	}
diff --git a/internal/handlers/utility_test.go b/internal/handlers/utility_test.go
index cb76075..7afa834 100644
--- a/internal/handlers/utility_test.go
+++ b/internal/handlers/utility_test.go
@@ -90,6 +90,16 @@ func TestUserhost(t *testing.T) {
 		t.Errorf("expected alice and bob, got %q", body)
 	}
 
+	msgs, lastID = sendAndPoll(tserver, token, lastID, map[string]any{
+		commandKey: irc.CmdUserhost,
+		bodyKey:    []string{"ghost"},
+	})
+
+	body = numericBody(t, msgs, "302")
+	if body != "" {
+		t.Errorf("expected an empty reply for ghost, got %q", body)
+	}
+
 	msgs, _ = sendAndPoll(tserver, token, lastID, map[string]any{
 		commandKey: irc.CmdUserhost,
 	})
@@ -187,8 +197,8 @@ func TestKill(t *testing.T) {
 		commandKey: irc.CmdKill,
 		bodyKey:    []string{"victim", "go away"},
 	})
-	if status != http.StatusOK {
-		t.Fatalf("expected 200, got %d: %v", status, result)
+	if status != http.StatusOK || result[statusKey] != "ok" {
+		t.Fatalf("expected 200 and status ok, got %d: %v", status, result)
 	}
 
 	msgs, _ = tserver.pollMessages(observerToken, observerLastID)
@@ -283,6 +293,7 @@ func TestUserMode(t *testing.T) {
 		{nick, "", "221", "+w"},
 		{strings.ToUpper(nick), "-w", "221", "+"},
 		{nick, "+z", "501", ""},
+		{nick, "+o", "501", ""},
 		{other, "", "502", ""},
 		{other, "-w", "502", ""},
 	} {
diff --git a/internal/ircserver/commands.go b/internal/ircserver/commands.go
index 99785ae..b5b0d75 100644
--- a/internal/ircserver/commands.go
+++ b/internal/ircserver/commands.go
@@ -1313,12 +1313,14 @@ func (c *Conn) handleVersion() {
 
 // handleAdmin replies with the server's admin info.
 func (c *Conn) handleAdmin() {
+	location1, location2, email := c.svc.AdminLines(c.serverSfx)
+
 	c.sendNumeric(
 		irc.RplAdminMe, c.serverSfx, "Administrative info",
 	)
-	c.sendNumeric(irc.RplAdminLoc1, "neoirc server")
-	c.sendNumeric(irc.RplAdminLoc2, "IRC over HTTP")
-	c.sendNumeric(irc.RplAdminEmail, "admin@"+c.serverSfx)
+	c.sendNumeric(irc.RplAdminLoc1, location1)
+	c.sendNumeric(irc.RplAdminLoc2, location2)
+	c.sendNumeric(irc.RplAdminEmail, email)
 }
 
 // handleInfo replies with the server's software info.
@@ -1352,7 +1354,7 @@ func (c *Conn) handleKill(
 		return
 	}
 
-	reason := "KILLed"
+	reason := ""
 	if len(msg.Params) > 1 {
 		reason = msg.Params[1]
 	}
diff --git a/internal/ircserver/conn_test.go b/internal/ircserver/conn_test.go
index 75601a1..d860d81 100644
--- a/internal/ircserver/conn_test.go
+++ b/internal/ircserver/conn_test.go
@@ -37,7 +37,9 @@ func newKillVictim(t *testing.T) (*ircserver.Conn, net.Conn) {
 
 // TestDisconnectDoesNotBlockOnUnresponsiveVictim checks
 // that Disconnect returns although the victim never reads,
-// so a KILL cannot stall the operator who sent it.
+// so a KILL cannot stall the operator who sent it. The
+// limit is well below one KillWriteWindow, so a Disconnect
+// that waits on any write to the victim fails.
 func TestDisconnectDoesNotBlockOnUnresponsiveVictim(
 	t *testing.T,
 ) {
@@ -53,7 +55,7 @@ func TestDisconnectDoesNotBlockOnUnresponsiveVictim(
 
 	select {
 	case <-returned:
-	case <-time.After(testTimeout):
+	case <-time.After(ircserver.KillWriteWindow / 4):
 		t.Fatal("Disconnect waited for the victim to read")
 	}
 }
diff --git a/internal/ircserver/export_test.go b/internal/ircserver/export_test.go
index 2b8e08c..4e665b2 100644
--- a/internal/ircserver/export_test.go
+++ b/internal/ircserver/export_test.go
@@ -56,6 +56,10 @@ func (s *Server) Listener() net.Listener {
 	return s.listener
 }
 
+// KillWriteWindow is how long Disconnect allows each write
+// to a killed victim.
+const KillWriteWindow = killWriteWindow
+
 // NewTestConn returns a Conn for nick on tcpConn, without a
 // server, database or service behind it.
 func NewTestConn(
diff --git a/internal/service/service.go b/internal/service/service.go
index 16e2fa4..361bcd3 100644
--- a/internal/service/service.go
+++ b/internal/service/service.go
@@ -119,6 +119,15 @@ func (s *Service) InfoLines() []string {
 	}
 }
 
+// AdminLines returns the texts of the RPL_ADMINLOC1,
+// RPL_ADMINLOC2 and RPL_ADMINEMAIL replies, in that order,
+// that ADMIN sends on both transports.
+func (s *Service) AdminLines(
+	serverName string,
+) (string, string, string) {
+	return "neoirc server", "IRC over HTTP", "admin@" + serverName
+}
+
 // UserhostReply returns the RPL_USERHOST text for the first
 // five of the given nicks: "nick=+user@host" entries joined
 // by spaces, with * after the nick of an operator and - in
@@ -199,7 +208,8 @@ func (s *Service) UnregisterWireConn(
 
 // KillUser carries out an operator's KILL: the target's
 // channel peers see it quit, its session is deleted, and
-// its IRC connection, if it has one, is closed.
+// its IRC connection, if it has one, is closed. An empty
+// reason is given as "KILLed".
 func (s *Service) KillUser(
 	ctx context.Context,
 	sessionID int64,
@@ -231,6 +241,10 @@ func (s *Service) KillUser(
 		}
 	}
 
+	if reason == "" {
+		reason = "KILLed"
+	}
+
 	quitReason := "Killed (" + nick + " (" + reason + "))"
 
 	s.BroadcastQuit(ctx, targetSID, targetNick, quitReason)
diff --git a/internal/service/service_test.go b/internal/service/service_test.go
index 933235d..2cc9ef2 100644
--- a/internal/service/service_test.go
+++ b/internal/service/service_test.go
@@ -406,6 +406,16 @@ func TestQueryUserMode(t *testing.T) {
 	if modes != "+ow" {
 		t.Errorf("expected +ow, got %s", modes)
 	}
+
+	// A flag that cannot be read is an error, not a flag
+	// that is unset.
+	cancelled, cancel := context.WithCancel(ctx)
+	cancel()
+
+	_, err = env.svc.QueryUserMode(cancelled, sid)
+	if !errors.Is(err, context.Canceled) {
+		t.Errorf("expected the read's error, got %v", err)
+	}
 }
 
 func TestUserhostReply(t *testing.T) {
@@ -453,6 +463,16 @@ func TestUserhostReply(t *testing.T) {
 	if strings.Count(reply, "bob=") != 5 {
 		t.Errorf("want 5 entries for 6 nicks, got %q", reply)
 	}
+
+	// A nick that cannot be looked up is an error, not a nick
+	// with no session.
+	cancelled, cancel := context.WithCancel(ctx)
+	cancel()
+
+	_, err = env.svc.UserhostReply(cancelled, []string{"alice"}, "srv")
+	if !errors.Is(err, context.Canceled) {
+		t.Errorf("want the lookup's error, got %v", err)
+	}
 }
 
 // userModes is the stored state of a session's user mode