diff --git a/pkg/api/http_server.go b/pkg/api/http_server.go
index f5ba1e92354..63d60710029 100644
--- a/pkg/api/http_server.go
+++ b/pkg/api/http_server.go
@@ -656,6 +656,7 @@ func (hs *HTTPServer) metricsEndpoint(ctx *web.Context) {
 	}
 
 	if hs.metricsEndpointBasicAuthEnabled() && !BasicAuthenticatedRequest(ctx.Req, hs.Cfg.MetricsEndpointBasicAuthUsername, hs.Cfg.MetricsEndpointBasicAuthPassword) {
+		ctx.Resp.Header().Set("WWW-Authenticate", `Basic realm="Grafana"`)
 		ctx.Resp.WriteHeader(http.StatusUnauthorized)
 		return
 	}