diff --git a/plugins/kubernetes-backend/src/service/KubernetesProxy.ts b/plugins/kubernetes-backend/src/service/KubernetesProxy.ts
index 15b99e4180..faf4a90846 100644
--- a/plugins/kubernetes-backend/src/service/KubernetesProxy.ts
+++ b/plugins/kubernetes-backend/src/service/KubernetesProxy.ts
@@ -172,8 +172,9 @@ export class KubernetesProxy {
             )?.toString(),
           };
 
-          const authHeader = req.header?.(HEADER_KUBERNETES_AUTH);
-          if (authHeader) {
+          const authHeader =
+            req.headers[HEADER_KUBERNETES_AUTH.toLocaleLowerCase()];
+          if (typeof authHeader === 'string') {
             req.headers.authorization = authHeader;
           } else {
             // Map Backstage-Kubernetes-Authorization-X-X headers to a KubernetesRequestAuth object