diff --git a/nameserver/entry.go b/nameserver/entry.go
index 312bcd4e..a3310423 100644
--- a/nameserver/entry.go
+++ b/nameserver/entry.go
@@ -18,7 +18,8 @@ type Entry struct {
 	ContainerID string
 	Origin      router.PeerName
 	Addr        address.Address
-	Hostname    string
+	Hostname    string // as supplied
+	lHostname   string // lowercased (not exported, so not encoded by gob)
 	Version     int
 	Tombstone   int64 // timestamp of when it was deleted
 }
@@ -69,7 +70,7 @@ func (e1 *Entry) less(e2 *Entry) bool {
 
 func (e1 *Entry) insensitiveLess(e2 *Entry) bool {
 	// Entries are kept sorted by Hostname, Origin, ContainerID then address
-	e1Hostname, e2Hostname := strings.ToLower(e1.Hostname), strings.ToLower(e2.Hostname)
+	e1Hostname, e2Hostname := e1.lHostname, e2.lHostname
 	switch {
 	case e1Hostname != e2Hostname:
 		return e1Hostname < e2Hostname
@@ -100,6 +101,10 @@ func (e1 *Entry) String() string {
 	return fmt.Sprintf("%s -> %s", e1.Hostname, e1.Addr.String())
 }
 
+func (e1 *Entry) addLowercase() {
+	e1.lHostname = strings.ToLower(e1.Hostname)
+}
+
 func check(es SortableEntries) error {
 	if !sort.IsSorted(es) {
 		return fmt.Errorf("Not sorted!")
@@ -126,7 +131,8 @@ func (es *Entries) checkAndPanic() *Entries {
 func (es *Entries) add(hostname, containerid string, origin router.PeerName, addr address.Address) Entry {
 	defer es.checkAndPanic().checkAndPanic()
 
-	entry := Entry{Hostname: hostname, Origin: origin, ContainerID: containerid, Addr: addr}
+	entry := Entry{Hostname: hostname, lHostname: strings.ToLower(hostname),
+		Origin: origin, ContainerID: containerid, Addr: addr}
 	i := sort.Search(len(*es), func(i int) bool {
 		return !(*es)[i].insensitiveLess(&entry)
 	})
@@ -204,14 +210,14 @@ func (es Entries) lookup(hostname string) Entries {
 
 	lowerHostname := strings.ToLower(hostname)
 	i := sort.Search(len(es), func(i int) bool {
-		return strings.ToLower(es[i].Hostname) >= lowerHostname
+		return es[i].lHostname >= lowerHostname
 	})
-	if i >= len(es) || strings.ToLower(es[i].Hostname) != lowerHostname {
+	if i >= len(es) || es[i].lHostname != lowerHostname {
 		return Entries{}
 	}
 
 	j := sort.Search(len(es)-i, func(j int) bool {
-		return strings.ToLower(es[i+j].Hostname) > lowerHostname
+		return es[i+j].lHostname > lowerHostname
 	})
 
 	return es[i : i+j]
@@ -228,6 +234,12 @@ func (es Entries) first(f func(*Entry) bool) (*Entry, error) {
 	return nil, fmt.Errorf("Not found")
 }
 
+func (es Entries) addLowercase() {
+	for i := range es {
+		es[i].addLowercase()
+	}
+}
+
 type GossipData struct {
 	Timestamp int64
 	Entries
@@ -246,6 +258,7 @@ func (g *GossipData) Decode(msg []byte) error {
 		return err
 	}
 
+	g.Entries.addLowercase() // lowercase strings not sent on the wire
 	sort.Sort(CaseInsensitive(g.Entries))
 	return nil
 }
diff --git a/nameserver/entry_test.go b/nameserver/entry_test.go
index e0640c1f..1e350e64 100644
--- a/nameserver/entry_test.go
+++ b/nameserver/entry_test.go
@@ -9,12 +9,17 @@ import (
 	"github.com/weaveworks/weave/router"
 )
 
+func l(es Entries) Entries {
+	es.addLowercase()
+	return es
+}
+
 func makeEntries(values string) Entries {
 	entries := make(Entries, len(values))
 	for i, c := range values {
 		entries[i] = Entry{Hostname: string(c)}
 	}
-	return entries
+	return l(entries)
 }
 
 func TestAdd(t *testing.T) {
@@ -24,21 +29,21 @@ func TestAdd(t *testing.T) {
 
 	entries := Entries{}
 	entries.add("A", "", router.UnknownPeerName, address.Address(0))
-	expected := Entries{
+	expected := l(Entries{
 		Entry{Hostname: "A", Origin: router.UnknownPeerName, Addr: address.Address(0)},
-	}
+	})
 	require.Equal(t, entries, expected)
 
 	entries.tombstone(router.UnknownPeerName, func(e *Entry) bool { return e.Hostname == "A" })
-	expected = Entries{
+	expected = l(Entries{
 		Entry{Hostname: "A", Origin: router.UnknownPeerName, Addr: address.Address(0), Version: 1, Tombstone: 1234},
-	}
+	})
 	require.Equal(t, entries, expected)
 
 	entries.add("A", "", router.UnknownPeerName, address.Address(0))
-	expected = Entries{
+	expected = l(Entries{
 		Entry{Hostname: "A", Origin: router.UnknownPeerName, Addr: address.Address(0), Version: 2},
-	}
+	})
 	require.Equal(t, entries, expected)
 }
 
@@ -56,14 +61,14 @@ func TestMerge(t *testing.T) {
 }
 
 func TestOldMerge(t *testing.T) {
-	e1 := Entries{Entry{Hostname: "A", Version: 0}}
-	diff := e1.merge(Entries{Entry{Hostname: "A", Version: 1}})
-	require.Equal(t, Entries{Entry{Hostname: "A", Version: 1}}, diff)
-	require.Equal(t, Entries{Entry{Hostname: "A", Version: 1}}, e1)
+	e1 := l(Entries{Entry{Hostname: "A", Version: 0}})
+	diff := e1.merge(l(Entries{Entry{Hostname: "A", Version: 1}}))
+	require.Equal(t, l(Entries{Entry{Hostname: "A", Version: 1}}), diff)
+	require.Equal(t, l(Entries{Entry{Hostname: "A", Version: 1}}), e1)
 
-	diff = e1.merge(Entries{Entry{Hostname: "A", Version: 0}})
+	diff = e1.merge(l(Entries{Entry{Hostname: "A", Version: 0}}))
 	require.Equal(t, Entries{}, diff)
-	require.Equal(t, Entries{Entry{Hostname: "A", Version: 1}}, e1)
+	require.Equal(t, l(Entries{Entry{Hostname: "A", Version: 1}}), e1)
 }
 
 func TestTombstone(t *testing.T) {
@@ -76,10 +81,10 @@ func TestTombstone(t *testing.T) {
 	es.tombstone(router.UnknownPeerName, func(e *Entry) bool {
 		return e.Hostname == "B"
 	})
-	expected := Entries{
+	expected := l(Entries{
 		Entry{Hostname: "A"},
 		Entry{Hostname: "B", Version: 1, Tombstone: 1234},
-	}
+	})
 	require.Equal(t, expected, es)
 }
 
@@ -93,18 +98,18 @@ func TestDelete(t *testing.T) {
 }
 
 func TestLookup(t *testing.T) {
-	es := Entries{
+	es := l(Entries{
 		Entry{Hostname: "A"},
 		Entry{Hostname: "B", ContainerID: "bar"},
 		Entry{Hostname: "B", ContainerID: "foo"},
 		Entry{Hostname: "C"},
-	}
+	})
 
 	have := es.lookup("B")
-	want := Entries{
+	want := l(Entries{
 		Entry{Hostname: "B", ContainerID: "bar"},
 		Entry{Hostname: "B", ContainerID: "foo"},
-	}
+	})
 	require.Equal(t, have, want)
 }
 
diff --git a/nameserver/nameserver_test.go b/nameserver/nameserver_test.go
index 5b518ad8..77b39b84 100644
--- a/nameserver/nameserver_test.go
+++ b/nameserver/nameserver_test.go
@@ -260,14 +260,14 @@ func TestTombstoneDeletion(t *testing.T) {
 	err = nameserver.Delete("hostname", "containerid", "", address.Address(0))
 	require.Nil(t, err)
 	require.Equal(t, []address.Address{}, nameserver.Lookup("hostname"))
-	require.Equal(t, Entries{{
+	require.Equal(t, l(Entries{Entry{
 		ContainerID: "containerid",
 		Origin:      peername,
 		Addr:        address.Address(0),
 		Hostname:    "hostname",
 		Version:     1,
 		Tombstone:   1234,
-	}}, nameserver.entries)
+	}}), nameserver.entries)
 
 	now = func() int64 { return 1234 + int64(tombstoneTimeout/time.Second) + 1 }
 	nameserver.deleteTombstones()