diff --git a/config/remote_generic/github_user.yaml b/config/remote_generic/github_user.yaml
index 557a8ca..d331a34 100644
--- a/config/remote_generic/github_user.yaml
+++ b/config/remote_generic/github_user.yaml
@@ -2,8 +2,18 @@ base_url: https://raw.githubusercontent.com
 description: GitHub User Content
 immutable_ttl: 0
 mutable_ttl: 7200
+mutable_patterns:
+  # victoria-metrics-k8s-stack dashboard sources; branch refs move, so these
+  # revalidate on mutable_ttl instead of caching immutably.
+  - "^dotdc/grafana-dashboards-kubernetes/master/dashboards/k8s-[a-z-]+\\.json$"
+  - "^monitoring-mixins/website/master/assets/etcd/dashboards/etcd\\.json$"
+  - "^prometheus-operator/kube-prometheus/main/manifests/grafana-dashboardDefinitions\\.yaml$"
 patterns:
   - "argoproj/argo-cd/.*.yaml$"
   - "datreeio/CRDs-catalog/main/.*.json$"
   - "kubernetes/kubernetes/.*.json$"
   - "yannh/kubernetes-json-schema/master/.*.json$"
+  # victoria-metrics-k8s-stack dashboard sources (also in mutable_patterns).
+  - "^dotdc/grafana-dashboards-kubernetes/master/dashboards/k8s-[a-z-]+\\.json$"
+  - "^monitoring-mixins/website/master/assets/etcd/dashboards/etcd\\.json$"
+  - "^prometheus-operator/kube-prometheus/main/manifests/grafana-dashboardDefinitions\\.yaml$"