diff --git a/helm/diffcalc-api/templates/pvc.yaml b/helm/diffcalc-api/templates/pvc.yaml
new file mode 100644
index 0000000..2190aa9
--- /dev/null
+++ b/helm/diffcalc-api/templates/pvc.yaml
@@ -0,0 +1,18 @@
+{{ if .Values.mongodb.persistence.createNew }}
+kind: PersistentVolumeClaim
+apiVersion: v1
+metadata:
+  name: {{ .Values.mongodb.persistence.existingClaim}}
+  annotations:
+    "helm.sh/hook": pre-install
+    "helm.sh/hook-weight": "-5"
+    "helm.sh/hook-delete-policy": before-hook-creation
+spec:
+  {{- with .Values.mongodb.persistence.accessModes }}
+  accessModes:
+    {{- toYaml . | nindent 4 }}
+  {{- end }}
+  resources:
+    requests:
+      storage: {{ .Values.mongodb.persistence.size }}
+{{ end }}
diff --git a/helm/diffcalc-api/values.yaml b/helm/diffcalc-api/values.yaml
index 45b8f4c..82aae9d 100644
--- a/helm/diffcalc-api/values.yaml
+++ b/helm/diffcalc-api/values.yaml
@@ -25,10 +25,12 @@ serviceAccount:
 
 podAnnotations: {}
 
-podSecurityContext: {}
+podSecurityContext:
+  {}
   # fsGroup: 2000
 
-securityContext: {}
+securityContext:
+  {}
   # capabilities:
   #   drop:
   #   - ALL
@@ -43,7 +45,8 @@ service:
 ingress:
   enabled: false
   className: ""
-  annotations: {}
+  annotations:
+    {}
     # kubernetes.io/ingress.class: nginx
     # kubernetes.io/tls-acme: "true"
   hosts:
@@ -56,7 +59,8 @@ ingress:
   #    hosts:
   #      - chart-example.local
 
-resources: {}
+resources:
+  {}
   # We usually recommend not to specify default resources and to leave this as a conscious
   # choice for the user. This also increases chances charts run on environments with little
   # resources, such as Minikube. If you do want to specify resources, uncomment the following
@@ -94,6 +98,9 @@ mongodb:
       cpu: 2
     requests:
       cpu: 1
+  persistence:
+    existingClaim: diffcalc-mongo-volume
+    createNew: false
 
 logging:
   level: "WARN"