diff --git a/pkg/tsdb/prometheus/buffered/time_series_query.go b/pkg/tsdb/prometheus/buffered/time_series_query.go
index 814fe2e1aed..914f906f9c7 100644
--- a/pkg/tsdb/prometheus/buffered/time_series_query.go
+++ b/pkg/tsdb/prometheus/buffered/time_series_query.go
@@ -322,7 +322,7 @@ func calculateRateInterval(interval time.Duration, scrapeInterval string, interv
 		return time.Duration(0)
 	}
 
-	rateInterval := time.Duration(int(math.Max(float64(interval+scrapeIntervalDuration), float64(4)*float64(scrapeIntervalDuration))))
+	rateInterval := time.Duration(int64(math.Max(float64(interval+scrapeIntervalDuration), float64(4)*float64(scrapeIntervalDuration))))
 	return rateInterval
 }