diff --git a/internal/preferences/device.go b/internal/preferences/device.go
index 9e6539d3b..33b52d1b7 100644
--- a/internal/preferences/device.go
+++ b/internal/preferences/device.go
@@ -10,6 +10,12 @@ import (
 	"fmt"
 )
 
+const (
+	devicePrefPrefix = "device"
+	prefDeviceID     = devicePrefPrefix + ".id"
+	prefDeviceName   = devicePrefPrefix + ".name"
+)
+
 // Device contains the device-specific preferences.
 type Device struct {
 	ID   string `toml:"id" validate:"required,ascii"`
@@ -20,23 +26,23 @@ var ErrSetDevicePreference = errors.New("could not set device preference")
 
 // SetDevicePreferences sets the device preferences.
 func SetDevicePreferences(device *Device) error {
-	if err := prefsSrc.Set("device.id", device.ID); err != nil {
+	if err := prefsSrc.Set(prefDeviceID, device.ID); err != nil {
 		return fmt.Errorf("%w: %w", ErrSetDevicePreference, err)
 	}
 
-	if err := prefsSrc.Set("device.name", device.Name); err != nil {
+	if err := prefsSrc.Set(prefDeviceName, device.Name); err != nil {
 		return fmt.Errorf("%w: %w", ErrSetDevicePreference, err)
 	}
 
 	return nil
 }
 
-// DeviceName retrieves the device name from the preferences.
-func DeviceName() string {
-	return prefsSrc.String("device.name")
-}
-
 // DeviceID retrieves the device ID from the preferences.
 func DeviceID() string {
-	return prefsSrc.String("device.id")
+	return prefsSrc.String(prefDeviceID)
+}
+
+// DeviceName retrieves the device name from the preferences.
+func DeviceName() string {
+	return prefsSrc.String(prefDeviceName)
 }
diff --git a/internal/preferences/hass.go b/internal/preferences/hass.go
index 7ee95c851..2bdad6a76 100644
--- a/internal/preferences/hass.go
+++ b/internal/preferences/hass.go
@@ -15,6 +15,17 @@ import (
 const (
 	WebsocketPath = "/api/websocket"
 	WebHookPath   = "/api/webhook/"
+
+	hassPrefPrefix       = "hass"
+	prefHassSecret       = hassPrefPrefix + ".secret"
+	prefHassAPIURL       = hassPrefPrefix + ".apiurl"
+	prefHassWebsocketURL = hassPrefPrefix + ".websocketurl"
+	prefHassWebhookID    = hassPrefPrefix + ".webhook_id"
+	prefHassCloudhookURL = hassPrefPrefix + ".cloudhook_url"
+	prefHassRemoteUIURL  = hassPrefPrefix + ".remote_ui_url"
+	regPrefPrefix        = "registration"
+	prefHassRegToken     = regPrefPrefix + ".token"
+	prefHassRegServer    = regPrefPrefix + ".server"
 )
 
 // Hass contains preferences related to connectivity to Home Assistant.
@@ -36,7 +47,7 @@ var (
 //
 //revive:disable:indent-error-flow
 func SetHassPreferences(hassPrefs *Hass, regPrefs *Registration) error {
-	if err := prefsSrc.Set("hass.secret", hassPrefs.Secret); err != nil {
+	if err := prefsSrc.Set(prefHassSecret, hassPrefs.Secret); err != nil {
 		return fmt.Errorf("%w: %w", ErrSetHassPreference, err)
 	}
 
@@ -44,7 +55,7 @@ func SetHassPreferences(hassPrefs *Hass, regPrefs *Registration) error {
 	if apiURL, err := generateAPIURL(hassPrefs, regPrefs); err != nil {
 		return fmt.Errorf("%w: %w", ErrSaveHassPreferences, err)
 	} else {
-		if err := prefsSrc.Set("hass.apiurl", apiURL); err != nil {
+		if err := prefsSrc.Set(prefHassAPIURL, apiURL); err != nil {
 			return fmt.Errorf("%w: %w", ErrSetHassPreference, err)
 		}
 	}
@@ -53,23 +64,23 @@ func SetHassPreferences(hassPrefs *Hass, regPrefs *Registration) error {
 	if websocketURL, err := generateWebsocketURL(regPrefs); err != nil {
 		return fmt.Errorf("%w: %w", ErrSaveHassPreferences, err)
 	} else {
-		if err := prefsSrc.Set("hass.websocketurl", websocketURL); err != nil {
+		if err := prefsSrc.Set(prefHassAPIURL, websocketURL); err != nil {
 			return fmt.Errorf("%w: %w", ErrSetHassPreference, err)
 		}
 	}
 
 	// Set the webhookID if present.
 	if hassPrefs.WebhookID != "" {
-		if err := prefsSrc.Set("hass.webhook_id", hassPrefs.WebhookID); err != nil {
+		if err := prefsSrc.Set(prefHassWebhookID, hassPrefs.WebhookID); err != nil {
 			return fmt.Errorf("%w: %w", ErrSetHassPreference, err)
 		}
 	}
 
-	if err := prefsSrc.Set("registration.server", regPrefs.Server); err != nil {
+	if err := prefsSrc.Set(prefHassRegServer, regPrefs.Server); err != nil {
 		return fmt.Errorf("%w: %w", ErrSetHassPreference, err)
 	}
 
-	if err := prefsSrc.Set("registration.token", regPrefs.Token); err != nil {
+	if err := prefsSrc.Set(prefHassRegToken, regPrefs.Token); err != nil {
 		return fmt.Errorf("%w: %w", ErrSetHassPreference, err)
 	}
 
@@ -79,37 +90,37 @@ func SetHassPreferences(hassPrefs *Hass, regPrefs *Registration) error {
 // RestAPIURL retrieves the configured Home Assistant Rest API URL from the
 // preferences.
 func RestAPIURL() string {
-	return prefsSrc.String("hass.apiurl")
+	return prefsSrc.String(prefHassAPIURL)
 }
 
 // RestAPIURL retrieves the configured Home Assistant websocket API URL from the
 // preferences.
 func WebsocketURL() string {
-	return prefsSrc.String("hass.websocketurl")
+	return prefsSrc.String(prefHassWebsocketURL)
 }
 
 // WebhookID retrieves the Go Hass Agent Webhook ID from the
 // preferences.
 func WebhookID() string {
-	return prefsSrc.String("hass.webhook_id")
+	return prefsSrc.String(prefHassWebhookID)
 }
 
 // Token retrieves the Go Hass Agent long-lived access token from the
 // preferences.
 func Token() string {
-	return prefsSrc.String("registration.token")
+	return prefsSrc.String(prefHassRegToken)
 }
 
 func generateAPIURL(hassPrefs *Hass, regPrefs *Registration) (string, error) {
 	switch {
 	case hassPrefs.CloudhookURL != "" && regPrefs.IgnoreHassURLs:
-		if err := prefsSrc.Set("hass.cloudhook_url", hassPrefs.CloudhookURL); err != nil {
+		if err := prefsSrc.Set(prefHassCloudhookURL, hassPrefs.CloudhookURL); err != nil {
 			return "", fmt.Errorf("%w: %w", ErrSetHassPreference, err)
 		}
 
 		return hassPrefs.CloudhookURL, nil
 	case hassPrefs.RemoteUIURL != "" && hassPrefs.WebhookID != "" && !regPrefs.IgnoreHassURLs:
-		if err := prefsSrc.Set("hass.remote_ui_url", hassPrefs.CloudhookURL); err != nil {
+		if err := prefsSrc.Set(prefHassRemoteUIURL, hassPrefs.CloudhookURL); err != nil {
 			return "", fmt.Errorf("%w: %w", ErrSetHassPreference, err)
 		}
 
diff --git a/internal/preferences/mqtt.go b/internal/preferences/mqtt.go
index 25195bc27..d16b493c6 100644
--- a/internal/preferences/mqtt.go
+++ b/internal/preferences/mqtt.go
@@ -13,6 +13,15 @@ import (
 	"github.com/knadh/koanf/v2"
 )
 
+const (
+	mqttPrefPrefix      = "mqtt"
+	prefMQTTServer      = mqttPrefPrefix + ".server"
+	prefMQTTUser        = mqttPrefPrefix + ".user"
+	prefMQTTPass        = mqttPrefPrefix + ".password"
+	prefMQTTTopicPrefix = mqttPrefPrefix + ".topic_prefx"
+	prefMQTTEnabled     = mqttPrefPrefix + ".enabled"
+)
+
 // MQTT contains preferences related to MQTT functionality in Go Hass Agent.
 type MQTT struct {
 	MQTTServer      string `toml:"server,omitempty" validate:"omitempty,uri" kong:"required,help='MQTT server URI. Required.',placeholder='scheme://some.host:port'"` //nolint:lll
@@ -27,23 +36,23 @@ var ErrSetMQTTPreference = errors.New("could not set MQTT preference")
 // SetMQTTPreferences will set Go Hass Agent's MQTT preferences to the given
 // values.
 func SetMQTTPreferences(prefs *MQTT) error {
-	if err := prefsSrc.Set("mqtt.server", prefs.MQTTServer); err != nil {
+	if err := prefsSrc.Set(prefMQTTServer, prefs.MQTTServer); err != nil {
 		return fmt.Errorf("%w: %w", ErrSetMQTTPreference, err)
 	}
 
-	if err := prefsSrc.Set("mqtt.user", prefs.MQTTUser); err != nil {
+	if err := prefsSrc.Set(prefMQTTUser, prefs.MQTTUser); err != nil {
 		return fmt.Errorf("%w: %w", ErrSetMQTTPreference, err)
 	}
 
-	if err := prefsSrc.Set("mqtt.password", prefs.MQTTPassword); err != nil {
+	if err := prefsSrc.Set(prefMQTTPass, prefs.MQTTPassword); err != nil {
 		return fmt.Errorf("%w: %w", ErrSetMQTTPreference, err)
 	}
 
-	if err := prefsSrc.Set("mqtt.topic_prefix", prefs.MQTTTopicPrefix); err != nil {
+	if err := prefsSrc.Set(prefMQTTTopicPrefix, prefs.MQTTTopicPrefix); err != nil {
 		return fmt.Errorf("%w: %w", ErrSetMQTTPreference, err)
 	}
 
-	if err := prefsSrc.Set("mqtt.enabled", prefs.MQTTEnabled); err != nil {
+	if err := prefsSrc.Set(prefMQTTEnabled, prefs.MQTTEnabled); err != nil {
 		return fmt.Errorf("%w: %w", ErrSetMQTTPreference, err)
 	}
 
@@ -54,7 +63,7 @@ func SetMQTTPreferences(prefs *MQTT) error {
 func GetMQTTPreferences() (*MQTT, error) {
 	var mqttPrefs MQTT
 	// Unmarshal config, overwriting defaults.
-	if err := prefsSrc.UnmarshalWithConf("mqtt", &mqttPrefs, koanf.UnmarshalConf{Tag: "toml"}); err != nil {
+	if err := prefsSrc.UnmarshalWithConf(mqttPrefPrefix, &mqttPrefs, koanf.UnmarshalConf{Tag: "toml"}); err != nil {
 		return nil, fmt.Errorf("%w: %w", ErrLoadPreferences, err)
 	}
 
@@ -63,7 +72,7 @@ func GetMQTTPreferences() (*MQTT, error) {
 
 // MQTTEnabled will return whether Go Hass Agent will use MQTT.
 func MQTTEnabled() bool {
-	return prefsSrc.Bool("mqtt.enabled")
+	return prefsSrc.Bool(prefMQTTEnabled)
 }
 
 // Server returns the broker URI from the preferences.
@@ -85,10 +94,6 @@ func (p *MQTT) Password() string {
 
 // TopicPrefix returns the prefix for topics on MQTT.
 func (p *MQTT) TopicPrefix() string {
-	if p.MQTTTopicPrefix == "" {
-		return MQTTTopicPrefix
-	}
-
 	return p.MQTTTopicPrefix
 }
 
diff --git a/internal/preferences/prefs.go b/internal/preferences/prefs.go
index 66c163a92..e70128f33 100644
--- a/internal/preferences/prefs.go
+++ b/internal/preferences/prefs.go
@@ -37,6 +37,8 @@ const (
 
 	DefaultServer = "http://localhost:8123"
 	DefaultSecret = "ALongSecretString"
+
+	prefRegistered = "registered"
 )
 
 var (
@@ -191,7 +193,7 @@ func Save(ctx context.Context) error {
 // SetRegistered sets whether Go Hass Agent has been registered with Home
 // Assistant.
 func SetRegistered(value bool) error {
-	if err := prefsSrc.Set("registration", value); err != nil {
+	if err := prefsSrc.Set(prefRegistered, value); err != nil {
 		return fmt.Errorf("%w: %w", ErrSetPreference, err)
 	}
 
@@ -200,7 +202,7 @@ func SetRegistered(value bool) error {
 
 // Registered returns the registration status of Go Hass Agent.
 func Registered() bool {
-	return prefsSrc.Bool("registered")
+	return prefsSrc.Bool(prefRegistered)
 }
 
 // checkPath checks that the given directory exists. If it doesn't it will be