diff --git a/cmd/promtool/main.go b/cmd/promtool/main.go
index 3dfbfb414..81c90b4ec 100644
--- a/cmd/promtool/main.go
+++ b/cmd/promtool/main.go
@@ -328,7 +328,7 @@ func main() {
 		os.Exit(backfillOpenMetrics(*importFilePath, *importDBPath, *importHumanReadable, *importQuiet, *maxBlockDuration))
 
 	case importRulesCmd.FullCommand():
-		os.Exit(checkErr(importRules(serverURL, *importRulesStart, *importRulesEnd, *importRulesOutputDir, *importRulesEvalInterval, *maxBlockDuration, *importRulesFiles...)))
+		os.Exit(checkErr(importRules(serverURL, httpRoundTripper, *importRulesStart, *importRulesEnd, *importRulesOutputDir, *importRulesEvalInterval, *maxBlockDuration, *importRulesFiles...)))
 	}
 }
 
@@ -1183,7 +1183,7 @@ func (j *jsonPrinter) printLabelValues(v model.LabelValues) {
 
 // importRules backfills recording rules from the files provided. The output are blocks of data
 // at the outputDir location.
-func importRules(url *url.URL, start, end, outputDir string, evalInterval, maxBlockDuration time.Duration, files ...string) error {
+func importRules(url *url.URL, roundTripper http.RoundTripper, start, end, outputDir string, evalInterval, maxBlockDuration time.Duration, files ...string) error {
 	ctx := context.Background()
 	var stime, etime time.Time
 	var err error
@@ -1213,7 +1213,8 @@ func importRules(url *url.URL, start, end, outputDir string, evalInterval, maxBl
 		maxBlockDuration: maxBlockDuration,
 	}
 	client, err := api.NewClient(api.Config{
-		Address: url.String(),
+		Address:      url.String(),
+		RoundTripper: roundTripper,
 	})
 	if err != nil {
 		return fmt.Errorf("new api client error: %w", err)