diff --git a/docs/cluster-connection.md b/docs/cluster-connection.md
index 8f1b922..98d432b 100644
--- a/docs/cluster-connection.md
+++ b/docs/cluster-connection.md
@@ -75,7 +75,19 @@ spec:
 
 > **Note:** The volume source can be any type that provides a file.
 
-> **Note:** The Helm chart does not support extra volumes yet.
+> **Tip:** When using the Helm chart, configure volumes via `extraVolumes` and `extraVolumeMounts` values:
+>
+> ```yaml
+> app:
+>   extraVolumes:
+>     - name: db-credentials
+>       secret:
+>         secretName: db-credentials-secret
+>   extraVolumeMounts:
+>     - name: db-credentials
+>       mountPath: /mnt/secrets
+>       readOnly: true
+> ```
 
 ### Examples
 
diff --git a/operator/src/main/helm/values.yaml b/operator/src/main/helm/values.yaml
new file mode 100644
index 0000000..5c15947
--- /dev/null
+++ b/operator/src/main/helm/values.yaml
@@ -0,0 +1,6 @@
+---
+# Workaround: quarkus-helm generates `extraVolumeMounts: {}` (object) instead of `[]` (array)
+# when the value path uses a container name filter like `containers.(name == ...)`.
+# This merge file corrects the default value type.
+app:
+  extraVolumeMounts: []
diff --git a/operator/src/main/kubernetes/kubernetes.yml b/operator/src/main/kubernetes/kubernetes.yml
index 037464e..a3f8dc3 100644
--- a/operator/src/main/kubernetes/kubernetes.yml
+++ b/operator/src/main/kubernetes/kubernetes.yml
@@ -8,3 +8,7 @@ spec:
     spec:
       affinity: {}
       imagePullSecrets: [~]
+      volumes: [~]
+      containers:
+        - name: postgresql-operator
+          volumeMounts: [~]
diff --git a/operator/src/main/resources/application.yml b/operator/src/main/resources/application.yml
index 3b5f766..ecbfdfa 100644
--- a/operator/src/main/resources/application.yml
+++ b/operator/src/main/resources/application.yml
@@ -113,6 +113,22 @@ quarkus:
         paths:
           - (kind == Deployment).spec.template.spec.affinity
         description: Kubernetes affinity configuration for Pod scheduling
+      extra-volumes:
+        property: extraVolumes
+        value:
+          - null
+        paths:
+          - (kind == Deployment).spec.template.spec.volumes
+        expression: "{{- if eq (toYaml .Values.app.extraVolumes | trim) \"- {}\" }} null{{- else }}{{ toYaml .Values.app.extraVolumes | nindent 8 }}{{- end }}"
+        description: Extra volumes to add to the operator pod
+      extra-volume-mounts:
+        property: extraVolumeMounts
+        value:
+          - null
+        paths:
+          - (kind == Deployment).spec.template.spec.containers.(name == postgresql-operator).volumeMounts
+        expression: "{{- if eq (toYaml .Values.app.extraVolumeMounts | trim) \"- {}\" }} null{{- else }}{{- toYaml .Values.app.extraVolumeMounts | nindent 12 }}{{- end }}"
+        description: Extra volume mounts to add to the operator container
       console-color:
         property: envs.QUARKUS_CONSOLE_COLOR
         value-as-bool: ${quarkus.console.color}
@@ -130,6 +146,12 @@ quarkus:
         "affinity":
           name: app.affinity
           type: object
+        "extraVolumeMounts":
+          name: app.extraVolumeMounts
+          type: array
+        "extraVolumes":
+          name: app.extraVolumes
+          type: array
     expressions:
       release-name-labels:
         expression: "{{ .Release.Name }}"
diff --git a/operator/src/test/java/it/aboutbits/postgresql/helm/HelmTest.java b/operator/src/test/java/it/aboutbits/postgresql/helm/HelmTest.java
index 7b864be..13a952d 100644
--- a/operator/src/test/java/it/aboutbits/postgresql/helm/HelmTest.java
+++ b/operator/src/test/java/it/aboutbits/postgresql/helm/HelmTest.java
@@ -92,6 +92,8 @@ void helmInstall_createsDeployment() throws IOException {
 
         Objects.requireNonNull(appValues, "appValues should not be null");
         assertThat(appValues.get("image")).isNotNull();
+        assertThat(appValues).containsKey("extraVolumes");
+        assertThat(appValues).containsKey("extraVolumeMounts");
 
         assertThat(chartPath.resolve("LICENSE")).exists();
         assertThat(chartPath.resolve("README.md")).exists();
@@ -173,9 +175,11 @@ void helmInstall_createsDeployment() throws IOException {
 
                     assertThat(deployment.getSpec())
                             .isNotNull()
-                            .satisfies(spec ->
-                                    assertThat(spec.getTemplate().getSpec().getImagePullSecrets()).isEmpty()
-                            );
+                            .satisfies(spec -> {
+                                    assertThat(spec.getTemplate().getSpec().getImagePullSecrets()).isEmpty();
+                                    assertThat(spec.getTemplate().getSpec().getVolumes()).isEmpty();
+                                    assertThat(spec.getTemplate().getSpec().getContainers().getFirst().getVolumeMounts()).isEmpty();
+                            });
 
                     var selector = deployment.getSpec().getSelector();