diff --git a/stable/kong/Chart.yaml b/stable/kong/Chart.yaml
index cd7ea8e2f7..cd1c5fdd47 100644
--- a/stable/kong/Chart.yaml
+++ b/stable/kong/Chart.yaml
@@ -12,5 +12,5 @@ maintainers:
 name: kong
 sources:
 - https://github.com/Kong/kong
-version: 0.18.3
+version: 0.18.4
 appVersion: 1.3
diff --git a/stable/kong/templates/deployment.yaml b/stable/kong/templates/deployment.yaml
index 169b69cc14..748e05319f 100644
--- a/stable/kong/templates/deployment.yaml
+++ b/stable/kong/templates/deployment.yaml
@@ -127,9 +127,9 @@ spec:
         - name: KONG_SMTP_HOST
           value: {{ .Values.enterprise.smtp.smtp_host }}
         - name: KONG_SMTP_PORT
-          value: {{ .Values.enterprise.smtp.smtp_port }}
+          value: {{ .Values.enterprise.smtp.smtp_port | quote }}
         - name: KONG_SMTP_STARTTLS
-          value: {{ .Values.enterprise.smtp.smtp_starttls }}
+          value: {{ .Values.enterprise.smtp.smtp_starttls | quote }}
         {{- if .Values.enterprise.smtp.auth.smtp_username }}
         - name: KONG_SMTP_USERNAME
           value: {{ .Values.enterprise.smtp.auth.smtp_username }}