diff --git a/metrics.go b/metrics.go
index e427360..9733ed4 100644
--- a/metrics.go
+++ b/metrics.go
@@ -16,7 +16,6 @@ import (
 	"runtime"
 	"sort"
 	"sync"
-	"time"
 
 	"github.com/valyala/histogram"
 )
@@ -119,8 +118,6 @@ func writeProcessMetrics(w io.Writer) {
 		runtime.Compiler, runtime.GOARCH, runtime.GOOS, runtime.GOROOT())
 }
 
-var startTime = time.Now()
-
 func registerMetric(name string, m metric) {
 	if err := validateMetric(name); err != nil {
 		panic(fmt.Errorf("BUG: invalid metric name %q: %s", name, err))