diff --git a/charts/gotenberg/CHANGELOG.md b/charts/gotenberg/CHANGELOG.md
index 54cec2d..d6979d8 100644
--- a/charts/gotenberg/CHANGELOG.md
+++ b/charts/gotenberg/CHANGELOG.md
@@ -1,5 +1,10 @@
 # Changelog
 
+## 1.5.1
+
+- Bump `gotenberg` version `8.7.0` -> `8.8.1`.
+- Fix [#39](https://github.com/MaikuMori/helm-charts/issues/39) (Thanks to Šimon Woidig | [@SimonWoidig](https://github.com/SimonWoidig))
+
 ## 1.5.0
 
 - Bump `gotenberg` version `8.5.1` -> `8.7.0`.
diff --git a/charts/gotenberg/Chart.yaml b/charts/gotenberg/Chart.yaml
index b1801ce..b4ce9a2 100644
--- a/charts/gotenberg/Chart.yaml
+++ b/charts/gotenberg/Chart.yaml
@@ -16,13 +16,13 @@ type: application
 # This is the chart version. This version number should be incremented each time you make changes
 # to the chart and its templates, including the app version.
 # Versions are expected to follow Semantic Versioning (https://semver.org/)
-version: "1.5.0"
+version: "1.5.1"
 
 # This is the version number of the application being deployed. This version number should be
 # incremented each time you make changes to the application. Versions are not expected to
 # follow Semantic Versioning. They should reflect the version the application is using.
 # It is recommended to use it with quotes.
-appVersion: "8.7.0"
+appVersion: "8.8.1"
 
 keywords:
   - gotenberg
diff --git a/charts/gotenberg/README.md b/charts/gotenberg/README.md
index bdaaa0e..fdb5093 100644
--- a/charts/gotenberg/README.md
+++ b/charts/gotenberg/README.md
@@ -1,7 +1,7 @@
 # Gotenberg
 
 [![Artifact Hub](https://img.shields.io/endpoint?url=https://artifacthub.io/badge/repository/gotenberg)](https://artifacthub.io/packages/helm/maikumori/gotenberg)
-![Version: 1.5.0](https://img.shields.io/badge/Version-1.5.0-informational?style=flat-square) ![Type: application](https://img.shields.io/badge/Type-application-informational?style=flat-square) ![AppVersion: 8.7.0](https://img.shields.io/badge/AppVersion-8.7.0-informational?style=flat-square)
+![Version: 1.5.1](https://img.shields.io/badge/Version-1.5.1-informational?style=flat-square) ![Type: application](https://img.shields.io/badge/Type-application-informational?style=flat-square) ![AppVersion: 8.8.1](https://img.shields.io/badge/AppVersion-8.8.1-informational?style=flat-square)
 
 This is a HELM chart for Gotenberg.
 
diff --git a/charts/gotenberg/templates/deployment.yaml b/charts/gotenberg/templates/deployment.yaml
index 6b38184..5b39605 100644
--- a/charts/gotenberg/templates/deployment.yaml
+++ b/charts/gotenberg/templates/deployment.yaml
@@ -243,9 +243,9 @@ spec:
       {{- with .Values.volumes }}
       volumes:
         {{- toYaml . | nindent 8 }}
-        {{- if .Values.api.tlsSecretName }}
+        {{- if $.Values.api.tlsSecretName }}
         - name: tls
           secret:
-            secretName: {{ .Values.api.tlsSecretName }}
+            secretName: {{ $.Values.api.tlsSecretName }}
         {{- end }}
       {{- end }}