diff --git a/plugin/metrics/handler.go b/plugin/metrics/handler.go
index 88fd2bcdb..077a301ff 100644
--- a/plugin/metrics/handler.go
+++ b/plugin/metrics/handler.go
@@ -33,7 +33,7 @@ func (m *Metrics) ServeDNS(ctx context.Context, w dns.ResponseWriter, r *dns.Msg
 		// see https://github.com/coredns/coredns/blob/master/core/dnsserver/server.go#L318
 		rc = status
 	}
-	plugin := m.authoritativePlugin(rw.Caller1, rw.Caller2, rw.Caller3)
+	plugin := m.authoritativePlugin(rw.Caller)
 	vars.Report(WithServer(ctx), state, zone, rcode.ToString(rc), plugin, rw.Len, rw.Start)
 
 	return status, err
@@ -43,22 +43,16 @@ func (m *Metrics) ServeDNS(ctx context.Context, w dns.ResponseWriter, r *dns.Msg
 func (m *Metrics) Name() string { return "prometheus" }
 
 // authoritativePlugin returns which of made the write, if none is found the empty string is returned.
-func (m *Metrics) authoritativePlugin(a, b, c string) string {
+func (m *Metrics) authoritativePlugin(caller [3]string) string {
 	// a b and c contain the full path of the caller, the plugin name 2nd last elements
 	// .../coredns/plugin/whoami/whoami.go --> whoami
 	// this is likely FS specific, so use filepath.
-	plug := filepath.Base(filepath.Dir(a))
-	if _, ok := m.plugins[plug]; ok {
-		return plug
-	}
-	plug = filepath.Base(filepath.Dir(b))
-	if _, ok := m.plugins[plug]; ok {
-		return plug
-	}
-	plug = filepath.Base(filepath.Dir(c))
-	if _, ok := m.plugins[plug]; ok {
-		return plug
-	}
+	for _, c := range caller {
+		plug := filepath.Base(filepath.Dir(c))
+		if _, ok := m.plugins[plug]; ok {
+			return plug
+		}
 
+	}
 	return ""
 }
diff --git a/plugin/metrics/recorder.go b/plugin/metrics/recorder.go
index fdfa1c2c4..2a6dec85b 100644
--- a/plugin/metrics/recorder.go
+++ b/plugin/metrics/recorder.go
@@ -10,10 +10,8 @@ import (
 // Recorder is a dnstest.Recorder specific to the metrics plugin.
 type Recorder struct {
 	*dnstest.Recorder
-	// CallerN holds the string return value of the call to runtime.Caller(N)
-	Caller1 string
-	Caller2 string
-	Caller3 string
+	// CallerN holds the string return value of the call to runtime.Caller(N+1)
+	Caller [3]string
 }
 
 // NewRecorder makes and returns a new Recorder.
@@ -22,9 +20,9 @@ func NewRecorder(w dns.ResponseWriter) *Recorder { return &Recorder{Recorder: dn
 // WriteMsg records the status code and calls the
 // underlying ResponseWriter's WriteMsg method.
 func (r *Recorder) WriteMsg(res *dns.Msg) error {
-	_, r.Caller1, _, _ = runtime.Caller(1)
-	_, r.Caller2, _, _ = runtime.Caller(2)
-	_, r.Caller3, _, _ = runtime.Caller(3)
+	_, r.Caller[0], _, _ = runtime.Caller(1)
+	_, r.Caller[1], _, _ = runtime.Caller(2)
+	_, r.Caller[2], _, _ = runtime.Caller(3)
 	r.Len += res.Len()
 	r.Msg = res
 	return r.ResponseWriter.WriteMsg(res)