diff --git a/charts/uptime-kuma/Chart.yaml b/charts/uptime-kuma/Chart.yaml
index 083cf4f..512b04b 100644
--- a/charts/uptime-kuma/Chart.yaml
+++ b/charts/uptime-kuma/Chart.yaml
@@ -11,4 +11,4 @@ name: uptime-kuma
 sources:
   - https://github.com/louislam/uptime-kuma
 type: application
-version: 2.21.0
+version: 2.21.1
diff --git a/charts/uptime-kuma/templates/statefulset.yaml b/charts/uptime-kuma/templates/statefulset.yaml
index 2237ba1..24d8c15 100644
--- a/charts/uptime-kuma/templates/statefulset.yaml
+++ b/charts/uptime-kuma/templates/statefulset.yaml
@@ -53,7 +53,7 @@ spec:
           imagePullPolicy: {{ .Values.image.pullPolicy }}
           env:
             - name: "UPTIME_KUMA_PORT"
-              value: {{ include "uptime-kuma.port" . }}
+              value: {{ include "uptime-kuma.port" . | quote }}
           {{- with .Values.podEnv }}
             {{- toYaml . | nindent 12 }}
           {{- end }}