diff --git a/util/stats/query_stats.go b/util/stats/query_stats.go
index 7a6c0f18ea..fc31445808 100644
--- a/util/stats/query_stats.go
+++ b/util/stats/query_stats.go
@@ -110,15 +110,25 @@ type querySamples struct {
 	TotalQueryableSamples        int        `json:"totalQueryableSamples"`
 }
 
-// QueryStats currently only holding query timings.
-type QueryStats struct {
+// BuiltinStats holds the statistics that Prometheus's core gathers.
+type BuiltinStats struct {
 	Timings queryTimings  `json:"timings,omitempty"`
 	Samples *querySamples `json:"samples,omitempty"`
 }
 
+// QueryStats holds BuiltinStats and any other stats the particular
+// implementation wants to collect.
+type QueryStats interface {
+	Builtin() BuiltinStats
+}
+
+func (s *BuiltinStats) Builtin() BuiltinStats {
+	return *s
+}
+
 // NewQueryStats makes a QueryStats struct with all QueryTimings found in the
 // given TimerGroup.
-func NewQueryStats(s *Statistics) *QueryStats {
+func NewQueryStats(s *Statistics) QueryStats {
 	var (
 		qt      queryTimings
 		samples *querySamples
@@ -150,7 +160,7 @@ func NewQueryStats(s *Statistics) *QueryStats {
 		samples.TotalQueryableSamplesPerStep = sp.totalSamplesPerStepPoints()
 	}
 
-	qs := QueryStats{Timings: qt, Samples: samples}
+	qs := BuiltinStats{Timings: qt, Samples: samples}
 	return &qs
 }
 
diff --git a/web/api/v1/api.go b/web/api/v1/api.go
index 67e01a777d..2c50297f1d 100644
--- a/web/api/v1/api.go
+++ b/web/api/v1/api.go
@@ -104,6 +104,15 @@ type RulesRetriever interface {
 	AlertingRules() []*rules.AlertingRule
 }
 
+type StatsRenderer func(context.Context, *stats.Statistics, string) stats.QueryStats
+
+func defaultStatsRenderer(ctx context.Context, s *stats.Statistics, param string) stats.QueryStats {
+	if param != "" {
+		return stats.NewQueryStats(s)
+	}
+	return nil
+}
+
 // PrometheusVersion contains build information about Prometheus.
 type PrometheusVersion struct {
 	Version   string `json:"version"`
@@ -177,15 +186,16 @@ type API struct {
 	ready                 func(http.HandlerFunc) http.HandlerFunc
 	globalURLOptions      GlobalURLOptions
 
-	db          TSDBAdminStats
-	dbDir       string
-	enableAdmin bool
-	logger      log.Logger
-	CORSOrigin  *regexp.Regexp
-	buildInfo   *PrometheusVersion
-	runtimeInfo func() (RuntimeInfo, error)
-	gatherer    prometheus.Gatherer
-	isAgent     bool
+	db            TSDBAdminStats
+	dbDir         string
+	enableAdmin   bool
+	logger        log.Logger
+	CORSOrigin    *regexp.Regexp
+	buildInfo     *PrometheusVersion
+	runtimeInfo   func() (RuntimeInfo, error)
+	gatherer      prometheus.Gatherer
+	isAgent       bool
+	statsRenderer StatsRenderer
 
 	remoteWriteHandler http.Handler
 	remoteReadHandler  http.Handler
@@ -222,6 +232,7 @@ func NewAPI(
 	buildInfo *PrometheusVersion,
 	gatherer prometheus.Gatherer,
 	registerer prometheus.Registerer,
+	statsRenderer StatsRenderer,
 ) *API {
 	a := &API{
 		QueryEngine:       qe,
@@ -246,10 +257,15 @@ func NewAPI(
 		buildInfo:        buildInfo,
 		gatherer:         gatherer,
 		isAgent:          isAgent,
+		statsRenderer:    defaultStatsRenderer,
 
 		remoteReadHandler: remote.NewReadHandler(logger, registerer, q, configFunc, remoteReadSampleLimit, remoteReadConcurrencyLimit, remoteReadMaxBytesInFrame),
 	}
 
+	if statsRenderer != nil {
+		a.statsRenderer = statsRenderer
+	}
+
 	if ap != nil {
 		a.remoteWriteHandler = remote.NewWriteHandler(logger, ap)
 	}
@@ -344,9 +360,9 @@ func (api *API) Register(r *route.Router) {
 }
 
 type queryData struct {
-	ResultType parser.ValueType  `json:"resultType"`
-	Result     parser.Value      `json:"result"`
-	Stats      *stats.QueryStats `json:"stats,omitempty"`
+	ResultType parser.ValueType `json:"resultType"`
+	Result     parser.Value     `json:"result"`
+	Stats      stats.QueryStats `json:"stats,omitempty"`
 }
 
 func invalidParamError(err error, parameter string) apiFuncResult {
@@ -399,10 +415,11 @@ func (api *API) query(r *http.Request) (result apiFuncResult) {
 	}
 
 	// Optional stats field in response if parameter "stats" is not empty.
-	var qs *stats.QueryStats
-	if r.FormValue("stats") != "" {
-		qs = stats.NewQueryStats(qry.Stats())
+	sr := api.statsRenderer
+	if sr == nil {
+		sr = defaultStatsRenderer
 	}
+	qs := sr(ctx, qry.Stats(), r.FormValue("stats"))
 
 	return apiFuncResult{&queryData{
 		ResultType: res.Value.Type(),
@@ -480,10 +497,11 @@ func (api *API) queryRange(r *http.Request) (result apiFuncResult) {
 	}
 
 	// Optional stats field in response if parameter "stats" is not empty.
-	var qs *stats.QueryStats
-	if r.FormValue("stats") != "" {
-		qs = stats.NewQueryStats(qry.Stats())
+	sr := api.statsRenderer
+	if sr == nil {
+		sr = defaultStatsRenderer
 	}
+	qs := sr(ctx, qry.Stats(), r.FormValue("stats"))
 
 	return apiFuncResult{&queryData{
 		ResultType: res.Value.Type(),
diff --git a/web/api/v1/api_test.go b/web/api/v1/api_test.go
index 6db0495929..55155f8bcf 100644
--- a/web/api/v1/api_test.go
+++ b/web/api/v1/api_test.go
@@ -30,6 +30,8 @@ import (
 	"testing"
 	"time"
 
+	"github.com/prometheus/prometheus/util/stats"
+
 	"github.com/go-kit/log"
 	"github.com/pkg/errors"
 	"github.com/prometheus/client_golang/prometheus"
@@ -522,6 +524,14 @@ func TestLabelNames(t *testing.T) {
 	}
 }
 
+type testStats struct {
+	Custom string `json:"custom"`
+}
+
+func (testStats) Builtin() (_ stats.BuiltinStats) {
+	return
+}
+
 func TestStats(t *testing.T) {
 	suite, err := promql.NewTest(t, ``)
 	require.NoError(t, err)
@@ -535,7 +545,7 @@ func TestStats(t *testing.T) {
 			return time.Unix(123, 0)
 		},
 	}
-	request := func(method string, param string) (*http.Request, error) {
+	request := func(method, param string) (*http.Request, error) {
 		u, err := url.Parse("http://example.com")
 		require.NoError(t, err)
 		q := u.Query()
@@ -555,6 +565,7 @@ func TestStats(t *testing.T) {
 
 	for _, tc := range []struct {
 		name     string
+		renderer StatsRenderer
 		param    string
 		expected func(*testing.T, interface{})
 	}{
@@ -574,7 +585,7 @@ func TestStats(t *testing.T) {
 				require.IsType(t, i, &queryData{})
 				qd := i.(*queryData)
 				require.NotNil(t, qd.Stats)
-				qs := qd.Stats
+				qs := qd.Stats.Builtin()
 				require.NotNil(t, qs.Timings)
 				require.Greater(t, qs.Timings.EvalTotalTime, float64(0))
 				require.NotNil(t, qs.Samples)
@@ -589,7 +600,7 @@ func TestStats(t *testing.T) {
 				require.IsType(t, i, &queryData{})
 				qd := i.(*queryData)
 				require.NotNil(t, qd.Stats)
-				qs := qd.Stats
+				qs := qd.Stats.Builtin()
 				require.NotNil(t, qs.Timings)
 				require.Greater(t, qs.Timings.EvalTotalTime, float64(0))
 				require.NotNil(t, qs.Samples)
@@ -597,8 +608,30 @@ func TestStats(t *testing.T) {
 				require.NotNil(t, qs.Samples.TotalQueryableSamplesPerStep)
 			},
 		},
+		{
+			name: "custom handler with known value",
+			renderer: func(ctx context.Context, s *stats.Statistics, p string) stats.QueryStats {
+				if p == "known" {
+					return testStats{"Custom Value"}
+				}
+				return nil
+			},
+			param: "known",
+			expected: func(t *testing.T, i interface{}) {
+				require.IsType(t, i, &queryData{})
+				qd := i.(*queryData)
+				require.NotNil(t, qd.Stats)
+				j, err := json.Marshal(qd.Stats)
+				require.NoError(t, err)
+				require.JSONEq(t, string(j), `{"custom":"Custom Value"}`)
+			},
+		},
 	} {
 		t.Run(tc.name, func(t *testing.T) {
+			before := api.statsRenderer
+			defer func() { api.statsRenderer = before }()
+			api.statsRenderer = tc.renderer
+
 			for _, method := range []string{http.MethodGet, http.MethodPost} {
 				ctx := context.Background()
 				req, err := request(method, tc.param)
diff --git a/web/web.go b/web/web.go
index 47d76590ec..0574549e5a 100644
--- a/web/web.go
+++ b/web/web.go
@@ -340,6 +340,7 @@ func New(logger log.Logger, o *Options) *Handler {
 		h.versionInfo,
 		o.Gatherer,
 		o.Registerer,
+		nil,
 	)
 
 	if o.RoutePrefix != "/" {