diff --git a/go.mod b/go.mod
index 1e3edbbc1..db030be2b 100644
--- a/go.mod
+++ b/go.mod
@@ -10,7 +10,7 @@ require (
 	github.com/fvbommel/sortorder v1.1.0
 	github.com/go-chi/chi/v5 v5.2.5
 	github.com/go-chi/cors v1.2.2
-	github.com/go-json-experiment/json v0.0.0-20260504200034-64a0a05799db
+	github.com/go-json-experiment/json v0.0.0-20260520185125-572e7c383686
 	github.com/go-viper/mapstructure/v2 v2.5.0
 	github.com/google/go-cmp v0.7.0
 	github.com/hashicorp/golang-lru/v2 v2.0.7
diff --git a/go.sum b/go.sum
index f8de8aed8..61d86073d 100644
--- a/go.sum
+++ b/go.sum
@@ -20,8 +20,8 @@ github.com/go-chi/chi/v5 v5.2.5 h1:Eg4myHZBjyvJmAFjFvWgrqDTXFyOzjj7YIm3L3mu6Ug=
 github.com/go-chi/chi/v5 v5.2.5/go.mod h1:X7Gx4mteadT3eDOMTsXzmI4/rwUpOwBHLpAfupzFJP0=
 github.com/go-chi/cors v1.2.2 h1:Jmey33TE+b+rB7fT8MUy1u0I4L+NARQlK6LhzKPSyQE=
 github.com/go-chi/cors v1.2.2/go.mod h1:sSbTewc+6wYHBBCW7ytsFSn836hqM7JxpglAy2Vzc58=
-github.com/go-json-experiment/json v0.0.0-20260504200034-64a0a05799db h1:EWTZKWQtY8ZehowJ8hV1E0GJEBiL2a0eJ7Zd/CU448w=
-github.com/go-json-experiment/json v0.0.0-20260504200034-64a0a05799db/go.mod h1:tphK2c80bpPhMOI4v6bIc2xWywPfbqi1Z06+RcrMkDg=
+github.com/go-json-experiment/json v0.0.0-20260520185125-572e7c383686 h1:NZBJxCpbHS1gzS6xAmyxbJznosZIIPk9IB42v62UvKA=
+github.com/go-json-experiment/json v0.0.0-20260520185125-572e7c383686/go.mod h1:tphK2c80bpPhMOI4v6bIc2xWywPfbqi1Z06+RcrMkDg=
 github.com/go-viper/mapstructure/v2 v2.5.0 h1:vM5IJoUAy3d7zRSVtIwQgBj7BiWtMPfmPEgAXnvj1Ro=
 github.com/go-viper/mapstructure/v2 v2.5.0/go.mod h1:oJDH3BJKyqBA2TXFhDsKDGDTlndYOZ6rGS0BRZIxGhM=
 github.com/golang-jwt/jwt/v5 v5.3.1 h1:kYf81DTWFe7t+1VvL7eS+jKFVWaUnK9cB1qbwn63YCY=
diff --git a/internal/config/models.go b/internal/config/models.go
index cde9eabb5..32fe9f71a 100644
--- a/internal/config/models.go
+++ b/internal/config/models.go
@@ -3,6 +3,9 @@ package config
 import (
 	"regexp"
 	"time"
+
+	jsonv2 "github.com/go-json-experiment/json"
+	"github.com/go-json-experiment/json/jsontext"
 )
 
 type AlertmanagerCORS struct {
@@ -217,16 +220,30 @@ type configSchema struct {
 		DefaultAlertmanagers []string `yaml:"defaultAlertmanagers" koanf:"defaultAlertmanagers"`
 	} `yaml:"silenceForm" koanf:"silenceForm"`
 	// nolint: maligned
-	UI struct {
-		Refresh              time.Duration `json:",format:nano"`
-		HideFiltersWhenIdle  bool          `yaml:"hideFiltersWhenIdle" koanf:"hideFiltersWhenIdle"`
-		ColorTitlebar        bool          `yaml:"colorTitlebar" koanf:"colorTitlebar"`
-		Theme                string        `yaml:"theme" koanf:"theme"`
-		Animations           bool          `yaml:"animations" koanf:"animations"`
-		MinimalGroupWidth    int           `yaml:"minimalGroupWidth" koanf:"minimalGroupWidth"`
-		AlertsPerGroup       int           `yaml:"alertsPerGroup" koanf:"alertsPerGroup"`
-		CollapseGroups       string        `yaml:"collapseGroups" koanf:"collapseGroups"`
-		MultiGridLabel       string        `yaml:"multiGridLabel" koanf:"multiGridLabel"`
-		MultiGridSortReverse bool          `yaml:"multiGridSortReverse" koanf:"multiGridSortReverse"`
+	UI UIConfig
+}
+
+type UIConfig struct {
+	Refresh              time.Duration `json:"Refresh"`
+	HideFiltersWhenIdle  bool          `yaml:"hideFiltersWhenIdle" koanf:"hideFiltersWhenIdle"`
+	ColorTitlebar        bool          `yaml:"colorTitlebar" koanf:"colorTitlebar"`
+	Theme                string        `yaml:"theme" koanf:"theme"`
+	Animations           bool          `yaml:"animations" koanf:"animations"`
+	MinimalGroupWidth    int           `yaml:"minimalGroupWidth" koanf:"minimalGroupWidth"`
+	AlertsPerGroup       int           `yaml:"alertsPerGroup" koanf:"alertsPerGroup"`
+	CollapseGroups       string        `yaml:"collapseGroups" koanf:"collapseGroups"`
+	MultiGridLabel       string        `yaml:"multiGridLabel" koanf:"multiGridLabel"`
+	MultiGridSortReverse bool          `yaml:"multiGridSortReverse" koanf:"multiGridSortReverse"`
+}
+
+func (ui UIConfig) MarshalJSON() ([]byte, error) {
+	type uiAlias UIConfig
+	aux := struct {
+		uiAlias
+		Refresh int64 `json:"Refresh"`
+	}{
+		uiAlias: uiAlias(ui),
+		Refresh: int64(ui.Refresh),
 	}
+	return jsonv2.Marshal(aux, jsontext.EscapeForHTML(true))
 }