diff --git a/internal/engine/experiment.go b/internal/engine/experiment.go
index 025077f..27eb22b 100644
--- a/internal/engine/experiment.go
+++ b/internal/engine/experiment.go
@@ -128,6 +128,7 @@ func (eaw *experimentAsyncWrapper) RunAsync(
 		defer close(out) // signal the reader we're done!
 		out <- &model.ExperimentAsyncTestKeys{
 			Extensions:         measurement.Extensions,
+			Input:              measurement.Input,
 			MeasurementRuntime: stop.Sub(start).Seconds(),
 			TestKeys:           measurement.TestKeys,
 		}
@@ -177,6 +178,7 @@ func (e *Experiment) MeasureAsync(
 		for tk := range in {
 			measurement := e.newMeasurement(input)
 			measurement.Extensions = tk.Extensions
+			measurement.Input = tk.Input
 			measurement.MeasurementRuntime = tk.MeasurementRuntime
 			measurement.TestKeys = tk.TestKeys
 			if err := measurement.Scrub(e.session.ProbeIP()); err != nil {
diff --git a/internal/engine/experiment/webstepsx/measurer.go b/internal/engine/experiment/webstepsx/measurer.go
index e5d4ad1..491f2d7 100644
--- a/internal/engine/experiment/webstepsx/measurer.go
+++ b/internal/engine/experiment/webstepsx/measurer.go
@@ -133,8 +133,6 @@ func (mx *Measurer) runAsync(ctx context.Context, sess model.ExperimentSession,
 		ctx, URL, measurex.NewHTTPRequestHeaderForMeasuring(), cookies)
 	for m := range in {
 		out <- &model.ExperimentAsyncTestKeys{
-			MeasurementRuntime: m.TotalRuntime.Seconds(),
-			TestKeys:           &TestKeys{URLMeasurement: m},
 			Extensions: map[string]int64{
 				archival.ExtHTTP.Name:         archival.ExtHTTP.V,
 				archival.ExtDNS.Name:          archival.ExtDNS.V,
@@ -142,6 +140,9 @@ func (mx *Measurer) runAsync(ctx context.Context, sess model.ExperimentSession,
 				archival.ExtTCPConnect.Name:   archival.ExtTCPConnect.V,
 				archival.ExtTLSHandshake.Name: archival.ExtTLSHandshake.V,
 			},
+			Input:              model.MeasurementTarget(m.URL),
+			MeasurementRuntime: m.TotalRuntime.Seconds(),
+			TestKeys:           &TestKeys{URLMeasurement: m},
 		}
 	}
 }
diff --git a/internal/engine/model/experiment.go b/internal/engine/model/experiment.go
index dcaeece..49e9e7f 100644
--- a/internal/engine/model/experiment.go
+++ b/internal/engine/model/experiment.go
@@ -24,14 +24,17 @@ type ExperimentSession interface {
 // ExperimentAsyncTestKeys is the type of test keys returned by an experiment
 // when running in async fashion rather than in sync fashion.
 type ExperimentAsyncTestKeys struct {
+	// Extensions contains the extensions used by this experiment.
+	Extensions map[string]int64
+
+	// Input is the input this measurement refers to.
+	Input MeasurementTarget
+
 	// MeasurementRuntime is the total measurement runtime.
 	MeasurementRuntime float64
 
 	// TestKeys contains the actual test keys.
 	TestKeys interface{}
-
-	// Extensions contains the extensions used by this experiment.
-	Extensions map[string]int64
 }
 
 // ExperimentMeasurerAsync is a measurer that can run in async fashion.