diff --git a/charts/prometheus-postgres-exporter/Chart.yaml b/charts/prometheus-postgres-exporter/Chart.yaml
index eb653698ea57..84e8c3be94d8 100644
--- a/charts/prometheus-postgres-exporter/Chart.yaml
+++ b/charts/prometheus-postgres-exporter/Chart.yaml
@@ -2,7 +2,7 @@ apiVersion: v2
 appVersion: "v0.16.0"
 description: A Helm chart for prometheus postgres-exporter
 name: prometheus-postgres-exporter
-version: 6.5.0
+version: 6.6.0
 home: https://github.com/prometheus-community/postgres_exporter
 sources:
 - https://github.com/prometheus-community/postgres_exporter
diff --git a/charts/prometheus-postgres-exporter/templates/deployment.yaml b/charts/prometheus-postgres-exporter/templates/deployment.yaml
index d7acda68696c..8c9165b5df94 100644
--- a/charts/prometheus-postgres-exporter/templates/deployment.yaml
+++ b/charts/prometheus-postgres-exporter/templates/deployment.yaml
@@ -159,7 +159,7 @@ spec:
             {{- toYaml . | nindent 12 }}
           {{- end }}
           volumeMounts:
-            {{- if .Values.config.postgresExporter }}
+            {{- if or .Values.config.postgresExporter .Values.config.existingSecret.enabled }}
             - name: postgres-exporter
               mountPath: /etc/postgres_exporter.yml
               subPath: postgres_exporter.yml
@@ -195,7 +195,13 @@ spec:
           defaultMode: 420
           name: {{ template "prometheus-postgres-exporter.fullname" . }}
         name: postgres-exporter
-      {{- end }}
+      {{- else if .Values.config.existingSecret.enabled }}
+      - secret:
+          defaultMode: 420
+          secretName: {{ .Values.config.existingSecret.name }}
+        name: postgres-exporter
+      {{ end}}
+
       {{- with .Values.extraVolumes }}
       {{ toYaml . | nindent 6 }}
       {{- end }}
diff --git a/charts/prometheus-postgres-exporter/values.yaml b/charts/prometheus-postgres-exporter/values.yaml
index 4686bce43e39..8d718f0ce717 100644
--- a/charts/prometheus-postgres-exporter/values.yaml
+++ b/charts/prometheus-postgres-exporter/values.yaml
@@ -189,6 +189,12 @@ config:
     #     options:
     #       sslmode: disable
 
+  # define an existing secret to be mounted as the config file
+  # needs to have the key 'postgres_exporter.yml'
+  existingSecret:
+    enabled: false
+    name: ""
+
 nodeSelector: {}
 
 tolerations: []
diff --git a/charts/prometheus/templates/pdb.yaml b/charts/prometheus/templates/pdb.yaml
index 7ffe67307116..fffbdc62fc87 100644
--- a/charts/prometheus/templates/pdb.yaml
+++ b/charts/prometheus/templates/pdb.yaml
@@ -11,5 +11,16 @@ spec:
   selector:
     matchLabels:
       {{- include "prometheus.server.matchLabels" . | nindent 6 }}
-  {{- toYaml $pdbSpec | nindent 2 }}
+  {{- if not (or (hasKey $pdbSpec "minAvailable") (hasKey $pdbSpec "maxUnavailable")) }}
+  maxUnavailable: 1
+  {{- end }}
+  {{- if hasKey $pdbSpec "minAvailable" }}
+  minAvailable: {{ $pdbSpec.minAvailable }}
+  {{- end }}
+  {{- if hasKey $pdbSpec "maxUnavailable" }}
+  maxUnavailable: {{ $pdbSpec.maxUnavailable }}
+  {{- end }}
+  {{- if hasKey $pdbSpec "unhealthyPodEvictionPolicy" }}
+  unhealthyPodEvictionPolicy: {{ $pdbSpec.unhealthyPodEvictionPolicy }}
+  {{- end }}
 {{- end }}
diff --git a/charts/prometheus/values.yaml b/charts/prometheus/values.yaml
index f5edbbf4fd09..a81d7a0a6fea 100644
--- a/charts/prometheus/values.yaml
+++ b/charts/prometheus/values.yaml
@@ -453,7 +453,7 @@ server:
   ##
   podDisruptionBudget:
     enabled: false
-    maxUnavailable: 1
+    # maxUnavailable: 1
     # minAvailable: 1
     ## unhealthyPodEvictionPolicy is available since 1.27.0 (beta)
     ## https://kubernetes.io/docs/tasks/run-application/configure-pdb/#unhealthy-pod-eviction-policy