diff --git a/main.go b/main.go
index 97c297b..ea9396c 100644
--- a/main.go
+++ b/main.go
@@ -30,19 +30,19 @@ type receiver struct {
 }
 
 type payload struct {
-	Status            string                 `json:"status"`
-	Alerts            []alert                `json:"alerts"`
-	GroupLabels       map[string]interface{} `json:"groupLabels"`
-	CommonLabels      map[string]interface{} `json:"commonLabels"`
-	CommonAnnotations map[string]interface{} `json:"commonAnnotations"`
-	ExternalURL       string                 `json:"externalURL"`
+	Status            string            `json:"status"`
+	Alerts            []alert           `json:"alerts"`
+	GroupLabels       map[string]string `json:"groupLabels"`
+	CommonLabels      map[string]string `json:"commonLabels"`
+	CommonAnnotations map[string]string `json:"commonAnnotations"`
+	ExternalURL       string            `json:"externalURL"`
 }
 
 type alert struct {
-	Status      string                 `json:"status"`
-	Labels      map[string]interface{} `json:"labels"`
-	Annotations map[string]interface{} `json:"annotations"`
-	Fingerprint fingerprint            `json:"fingerprint"`
+	Status      string            `json:"status"`
+	Labels      map[string]string `json:"labels"`
+	Annotations map[string]string `json:"annotations"`
+	Fingerprint fingerprint       `json:"fingerprint"`
 }
 
 type notification struct {
diff --git a/silence.go b/silence.go
index ffc23db..b5c5a6b 100644
--- a/silence.go
+++ b/silence.go
@@ -28,8 +28,8 @@ type matcher struct {
 }
 
 type silenceBody struct {
-	AlertManagerURL string                 `json:"alertmanagerURL"`
-	Labels          map[string]interface{} `json:"labels"`
+	AlertManagerURL string            `json:"alertmanagerURL"`
+	Labels          map[string]string `json:"labels"`
 }
 
 func (rcv *receiver) handleSilences(w http.ResponseWriter, r *http.Request) {
@@ -64,7 +64,7 @@ func (rcv *receiver) handleSilences(w http.ResponseWriter, r *http.Request) {
 	for key, value := range sb.Labels {
 		m := matcher{
 			Name:    key,
-			Value:   value.(string),
+			Value:   value,
 			IsRegex: false,
 			IsEqual: true,
 		}