diff --git a/argocd/applications/prometheus-operator.yaml b/argocd/applications/monitoring.yaml
similarity index 70%
rename from argocd/applications/prometheus-operator.yaml
rename to argocd/applications/monitoring.yaml
index 0680754..9fc09b7 100644
--- a/argocd/applications/prometheus-operator.yaml
+++ b/argocd/applications/monitoring.yaml
@@ -1,13 +1,13 @@
 apiVersion: argoproj.io/v1alpha1
 kind: Application
 metadata:
-  name: prometheus-operator
+  name: monitoring
 spec:
   project: default
   source:
     repoURL: git@github.com:hashbang/gitops.git
-    path: prometheus-operator/
+    path: monitoring/
     targetRevision: HEAD
   destination:
     server: https://kubernetes.default.svc
-    namespace: prometheus-operator
+    namespace: monitoring
diff --git a/prometheus-operator/kustomization.yaml b/monitoring/kustomization.yaml
similarity index 50%
rename from prometheus-operator/kustomization.yaml
rename to monitoring/kustomization.yaml
index 6b8bec0..e3b00dc 100644
--- a/prometheus-operator/kustomization.yaml
+++ b/monitoring/kustomization.yaml
@@ -1,12 +1,8 @@
 apiVersion: kustomize.config.k8s.io/v1beta1
 kind: Kustomization
-namespace: prometheus-operator
 resources:
-  - namespace.yaml
-  # v0.38.1
-  - github.com/coreos/prometheus-operator?ref=00cbd4911f931380cf9e19d771d7ebae1ec0a807
-  - prometheus-operator-metrics.yaml
-  - prometheus-instance.yaml
+  # release-0.4; held back due to 0.5 not supporting Kubernetes 1.18
+  - github.com/coreos/kube-prometheus?ref=ee8077db04965d6b4d9e6a328d5283dd6ba71d33
 images:
   - name: quay.io/coreos/prometheus-operator:v0.38.1
     digest: sha256:62b8cf466e9b238a9fcf0bcba74562c8833e7451042321e323a46de3f1dbe1bc
diff --git a/prometheus-operator/namespace.yaml b/prometheus-operator/namespace.yaml
deleted file mode 100644
index a586749..0000000
--- a/prometheus-operator/namespace.yaml
+++ /dev/null
@@ -1,4 +0,0 @@
-apiVersion: v1
-kind: Namespace
-metadata:
-  name: prometheus-operator
diff --git a/prometheus-operator/prometheus-instance.yaml b/prometheus-operator/prometheus-instance.yaml
deleted file mode 100644
index 8f36143..0000000
--- a/prometheus-operator/prometheus-instance.yaml
+++ /dev/null
@@ -1,100 +0,0 @@
-# https://github.com/coreos/prometheus-operator/blob/master/Documentation/user-guides/getting-started.md#enable-rbac-rules-for-prometheus-pods
-apiVersion: v1
-kind: ServiceAccount
-metadata:
-  name: prometheus
----
-apiVersion: rbac.authorization.k8s.io/v1beta1
-kind: ClusterRole
-metadata:
-  name: prometheus
-rules:
-- apiGroups: [""]
-  resources:
-  - nodes
-  - nodes/metrics
-  - services
-  - endpoints
-  - pods
-  verbs: ["get", "list", "watch"]
-- apiGroups: [""]
-  resources:
-  - configmaps
-  verbs: ["get"]
-- nonResourceURLs: ["/metrics"]
-  verbs: ["get"]
----
-apiVersion: rbac.authorization.k8s.io/v1beta1
-kind: ClusterRoleBinding
-metadata:
-  name: prometheus
-roleRef:
-  apiGroup: rbac.authorization.k8s.io
-  kind: ClusterRole
-  name: prometheus
-subjects:
-- kind: ServiceAccount
-  name: prometheus
-  namespace: default
----
-# https://github.com/coreos/prometheus-operator/blob/master/Documentation/user-guides/getting-started.md#include-servicemonitors
-apiVersion: monitoring.coreos.com/v1
-kind: Prometheus
-metadata:
-  name: prometheus
-spec:
-  serviceAccountName: prometheus
-  serviceMonitorNamespaceSelector: {} # An empty label selector matches all objects.
-  serviceMonitorSelector:
-    matchLabels:
-      prometheusInstance: default
-  podMonitorNamespaceSelector: {} # An empty label selector matches all objects.
-  podMonitorSelector:
-    matchLabels:
-      prometheusInstance: default
-  resources:
-    requests:
-      memory: 400Mi
-  enableAdminAPI: false
-  # Hash lock prometheus container
-  sha: e4ca62c0d62f3e886e684806dfe9d4e0cda60d54986898173c1083856cfda0f4
-  # Hash lock helper containers
-  containers:
-    - name: prometheus-config-reloader
-      image: quay.io/coreos/prometheus-config-reloader@sha256:d1cce64093d4a850d28726ec3e48403124808f76567b5bd7b26e4416300996a7
-    - name: rules-configmap-reloader
-      image: docker.io/jimmidyson/configmap-reload@sha256:d107c7a235c266273b1c3502a391fec374430e5625539403d0de797fa9c556a2
-    # - name: thanos-sidecar
-    #   image:
----
-apiVersion: v1
-kind: Service
-metadata:
-  name: prometheus
-  labels:
-    app: prometheus
-    prometheus: prometheus
-spec:
-  ports:
-  - name: web
-    port: 9090
-    protocol: TCP
-    targetPort: web
-  selector:
-    prometheus: prometheus
----
-apiVersion: monitoring.coreos.com/v1
-kind: ServiceMonitor
-metadata:
-  name: prometheus-metrics
-  annotations:
-    argocd.argoproj.io/sync-options: SkipDryRunOnMissingResource=true
-  labels:
-    prometheusInstance: default
-spec:
-  selector:
-    matchLabels:
-      app: prometheus
-      prometheus: prometheus
-  endpoints:
-  - port: web
diff --git a/prometheus-operator/prometheus-operator-metrics.yaml b/prometheus-operator/prometheus-operator-metrics.yaml
deleted file mode 100644
index 00f78b6..0000000
--- a/prometheus-operator/prometheus-operator-metrics.yaml
+++ /dev/null
@@ -1,14 +0,0 @@
-apiVersion: monitoring.coreos.com/v1
-kind: ServiceMonitor
-metadata:
-  name: prometheus-operator-metrics
-  annotations:
-    argocd.argoproj.io/sync-options: SkipDryRunOnMissingResource=true
-  labels:
-    prometheusInstance: default
-spec:
-  selector:
-    matchLabels:
-      app.kubernetes.io/name: prometheus-operator
-  endpoints:
-  - port: http