diff --git a/fw-settings/config.go b/fw-settings/config.go
index a7c8fe2..15be978 100644
--- a/fw-settings/config.go
+++ b/fw-settings/config.go
@@ -27,7 +27,7 @@ func loadConfig(win *gtk.Window, b *builder, dbus *dbusObject) {
 	}
 
 	if lvl, ok := conf["log_level"].(int32); ok {
-		if id, ok := sgfw.LevelToId[lvl]; ok {
+		if id, ok := sgfw.LevelToID[lvl]; ok {
 			levelCombo.SetActiveID(id)
 		}
 	}
@@ -45,7 +45,7 @@ func loadConfig(win *gtk.Window, b *builder, dbus *dbusObject) {
 	}
 	b.ConnectSignals(map[string]interface{}{
 		"on_level_combo_changed": func() {
-			if lvl, ok := sgfw.IdToLevel[levelCombo.GetActiveID()]; ok {
+			if lvl, ok := sgfw.IDToLevel[levelCombo.GetActiveID()]; ok {
 				dbus.setConfig("log_level", lvl)
 			}
 		},
diff --git a/sgfw/dns.go b/sgfw/dns.go
index b963ab4..412f1b5 100644
--- a/sgfw/dns.go
+++ b/sgfw/dns.go
@@ -14,7 +14,7 @@ type dnsCache struct {
 	done  chan struct{}
 }
 
-func NewDnsCache() *dnsCache {
+func newDnsCache() *dnsCache {
 	return &dnsCache{
 		ipMap: make(map[string]string),
 		done:  make(chan struct{}),
diff --git a/sgfw/log.go b/sgfw/log.go
index a0113e9..e634d73 100644
--- a/sgfw/log.go
+++ b/sgfw/log.go
@@ -8,7 +8,8 @@ import (
 	"github.com/op/go-logging"
 )
 
-var LevelToId = map[int32]string{
+// Log level conversion map
+var LevelToID = map[int32]string{
 	int32(logging.ERROR):   "error",
 	int32(logging.WARNING): "warning",
 	int32(logging.NOTICE):  "notice",
@@ -16,9 +17,10 @@ var LevelToId = map[int32]string{
 	int32(logging.DEBUG):   "debug",
 }
 
-var IdToLevel = func() map[string]int32 {
+// Log level string conversion
+var IDToLevel = func() map[string]int32 {
 	m := make(map[string]int32)
-	for k, v := range LevelToId {
+	for k, v := range LevelToID {
 		m[v] = k
 	}
 	return m
diff --git a/sgfw/sgfw.go b/sgfw/sgfw.go
index f548c90..a551465 100644
--- a/sgfw/sgfw.go
+++ b/sgfw/sgfw.go
@@ -130,7 +130,7 @@ func Main() {
 
 	fw := &Firewall{
 		dbus:            ds,
-		dns:             NewDnsCache(),
+		dns:             newDnsCache(),
 		enabled:         true,
 		logBackend:      logBackend,
 		policyMap:       make(map[string]*Policy),