diff --git a/pkg/tsdb/prometheus/prometheus.go b/pkg/tsdb/prometheus/prometheus.go
index 458958b8570..6319addf85d 100644
--- a/pkg/tsdb/prometheus/prometheus.go
+++ b/pkg/tsdb/prometheus/prometheus.go
@@ -185,6 +185,7 @@ func getClient(dsInfo *DatasourceInfo, s *Service) (apiv1.API, error) {
 		Timeouts:  dsInfo.HTTPClientOpts.Timeouts,
 		TLS:       dsInfo.HTTPClientOpts.TLS,
 		BasicAuth: dsInfo.HTTPClientOpts.BasicAuth,
+		Headers:   dsInfo.HTTPClientOpts.Headers,
 	}
 
 	customMiddlewares := customQueryParametersMiddleware(plog)