diff --git a/kustomize/base/flagger/deployment.yaml b/kustomize/base/flagger/deployment.yaml
index af0c3f60..f0bd8b13 100644
--- a/kustomize/base/flagger/deployment.yaml
+++ b/kustomize/base/flagger/deployment.yaml
@@ -53,4 +53,5 @@ spec:
             memory: "32Mi"
             cpu: "10m"
         securityContext:
+          readOnlyRootFilesystem: true
           runAsUser: 10001