diff --git a/jsonnet/kube-prometheus/components/prometheus.libsonnet b/jsonnet/kube-prometheus/components/prometheus.libsonnet
index f72f19f9cfa2e96c0f53146fb0ead8d6fe7c029f..089d7bb652ff6d079eb930e567dd55f66291f601 100644
--- a/jsonnet/kube-prometheus/components/prometheus.libsonnet
+++ b/jsonnet/kube-prometheus/components/prometheus.libsonnet
@@ -116,6 +116,18 @@ function(params) {
           port: o.port,
           protocol: 'TCP',
         }, p.service.spec.ports),
+      }, {
+        from: [{
+          podSelector: {
+            matchLabels: {
+              'app.kubernetes.io/name': 'prometheus-adapter',
+            },
+          },
+        }],
+        ports: [{
+          port: 9090,
+          protocol: 'TCP',
+        }],
       }, {
         from: [{
           podSelector: {
diff --git a/manifests/prometheus-networkPolicy.yaml b/manifests/prometheus-networkPolicy.yaml
index f0f6c90b7ccc5c81bad6c9940765bad797b56a62..c25a4457bba1031e8a1a9374999ef6eef5aba229 100644
--- a/manifests/prometheus-networkPolicy.yaml
+++ b/manifests/prometheus-networkPolicy.yaml
@@ -22,6 +22,13 @@ spec:
       protocol: TCP
     - port: 8080
       protocol: TCP
+  - from:
+    - podSelector:
+        matchLabels:
+          app.kubernetes.io/name: prometheus-adapter
+    ports:
+    - port: 9090
+      protocol: TCP
   - from:
     - podSelector:
         matchLabels: