diff --git a/router/connection_maker.go b/router/connection_maker.go
index 349098be..50d65cfb 100644
--- a/router/connection_maker.go
+++ b/router/connection_maker.go
@@ -47,7 +47,7 @@ func (cm *ConnectionMaker) Start() {
 
 func (cm *ConnectionMaker) InitiateConnection(address string) {
 	cm.actionChan <- func() bool {
-		cm.cmdLineAddress[NormalisePeerAddr(address)] = struct{}{}
+		cm.cmdLineAddress[NormalisePeerAddr(address)] = void
 		if target, found := cm.targets[address]; found {
 			target.tryAfter, target.tryInterval = tryImmediately()
 		}
@@ -117,13 +117,13 @@ func (cm *ConnectionMaker) checkStateAndAttemptConnections() time.Duration {
 	ourConnectedPeers := make(PeerNameSet)
 	ourConnectedTargets := make(map[string]struct{})
 	for _, conn := range cm.ourself.Connections() {
-		ourConnectedPeers[conn.Remote().Name] = struct{}{}
-		ourConnectedTargets[conn.RemoteTCPAddr()] = struct{}{}
+		ourConnectedPeers[conn.Remote().Name] = void
+		ourConnectedTargets[conn.RemoteTCPAddr()] = void
 	}
 
 	addTarget := func(address string) {
 		if _, connected := ourConnectedTargets[address]; !connected {
-			validTarget[address] = struct{}{}
+			validTarget[address] = void
 			cm.addTarget(address)
 		}
 	}
diff --git a/router/mocks_test.go b/router/mocks_test.go
index 82016bc2..3e10bc0c 100644
--- a/router/mocks_test.go
+++ b/router/mocks_test.go
@@ -50,7 +50,7 @@ func newMockConnection(from, to *Peer) Connection {
 func checkEqualConns(t *testing.T, ourName PeerName, got, wanted map[PeerName]Connection) {
 	checkConns := make(PeerNameSet)
 	for _, conn := range wanted {
-		checkConns[conn.Remote().Name] = struct{}{}
+		checkConns[conn.Remote().Name] = void
 	}
 	for _, conn := range got {
 		remoteName := conn.Remote().Name
diff --git a/router/peers.go b/router/peers.go
index 1e9d7eca..31a8cc1f 100644
--- a/router/peers.go
+++ b/router/peers.go
@@ -171,7 +171,7 @@ func (peers *Peers) garbageCollect() []*Peer {
 func setFromPeersMap(peers map[PeerName]*Peer) PeerNameSet {
 	names := make(PeerNameSet)
 	for name := range peers {
-		names[name] = struct{}{}
+		names[name] = void
 	}
 	return names
 }
diff --git a/router/router.go b/router/router.go
index 6e22b6d4..7ef3a9a2 100644
--- a/router/router.go
+++ b/router/router.go
@@ -358,14 +358,14 @@ type TopologyGossipData struct {
 func NewTopologyGossipData(peers *Peers, update ...*Peer) *TopologyGossipData {
 	names := make(PeerNameSet)
 	for _, p := range update {
-		names[p.Name] = struct{}{}
+		names[p.Name] = void
 	}
 	return &TopologyGossipData{peers: peers, update: names}
 }
 
 func (d *TopologyGossipData) Merge(other GossipData) {
 	for name := range other.(*TopologyGossipData).update {
-		d.update[name] = struct{}{}
+		d.update[name] = void
 	}
 }
 
diff --git a/router/utils.go b/router/utils.go
index 3153db7f..1545b23d 100644
--- a/router/utils.go
+++ b/router/utils.go
@@ -10,6 +10,8 @@ import (
 	"net"
 )
 
+var void = struct{}{}
+
 func checkFatal(e error) {
 	if e != nil {
 		log.Fatal(e)