diff --git a/staging/kube-oidc-proxy/templates/deployment.yaml b/staging/kube-oidc-proxy/templates/deployment.yaml
index 4432c3e7ef..9b82f22cde 100644
--- a/staging/kube-oidc-proxy/templates/deployment.yaml
+++ b/staging/kube-oidc-proxy/templates/deployment.yaml
@@ -51,6 +51,8 @@ spec:
           - "--oidc-username-claim=$(OIDC_USERNAME_CLAIM)"
           {{- if or .Values.oidc.caPEM .Values.oidc.caSecretName }}
           - "--oidc-ca-file=/etc/oidc/oidc-ca.pem"
+          {{- else }}
+          - "--oidc-ca-file=/var/run/secrets/kubernetes.io/serviceaccount/ca.crt"
           {{ end }}
           {{- if .Values.oidc.usernamePrefix }}
           - "--oidc-username-prefix=$(OIDC_USERNAME_PREFIX)"