diff --git a/test/acceptance.go b/test/acceptance.go
index 67b1c8bc..7bd4630c 100644
--- a/test/acceptance.go
+++ b/test/acceptance.go
@@ -36,6 +36,13 @@ type AcceptanceOpts struct {
 	baseTime  time.Time
 }
 
+func (opts *AcceptanceOpts) alertString(a *model.Alert) string {
+	if a.EndsAt.IsZero() {
+		return fmt.Sprintf("%s[%v:]", a, opts.relativeTime(a.StartsAt))
+	}
+	return fmt.Sprintf("%s[%v:%v]", a, opts.relativeTime(a.StartsAt), opts.relativeTime(a.EndsAt))
+}
+
 // expandTime returns the absolute time for the relative time
 // calculated from the test's base time.
 func (opts *AcceptanceOpts) expandTime(rel float64) time.Time {
diff --git a/test/acceptance/inhibit_test.go b/test/acceptance/inhibit_test.go
index d92690c0..c0e52960 100644
--- a/test/acceptance/inhibit_test.go
+++ b/test/acceptance/inhibit_test.go
@@ -52,15 +52,15 @@ inhibit_rules:
 	am.Push(At(2.2), Alert("alertname", "JobDown", "job", "testjob", "zone", "aa"))
 
 	co.Want(Between(2, 2.5),
-		Alert("alertname", "test1", "job", "testjob", "zone", "aa"),
-		Alert("alertname", "InstanceDown", "job", "testjob", "zone", "aa"),
-		Alert("alertname", "InstanceDown", "job", "testjob", "zone", "ab"),
+		Alert("alertname", "test1", "job", "testjob", "zone", "aa").Active(1),
+		Alert("alertname", "InstanceDown", "job", "testjob", "zone", "aa").Active(1),
+		Alert("alertname", "InstanceDown", "job", "testjob", "zone", "ab").Active(1),
 	)
 
 	co.Want(Between(3, 3.5),
-		Alert("alertname", "test1", "job", "testjob", "zone", "aa"),
-		Alert("alertname", "InstanceDown", "job", "testjob", "zone", "ab"),
-		Alert("alertname", "JobDown", "job", "testjob", "zone", "aa"),
+		Alert("alertname", "test1", "job", "testjob", "zone", "aa").Active(1),
+		Alert("alertname", "InstanceDown", "job", "testjob", "zone", "ab").Active(1),
+		Alert("alertname", "JobDown", "job", "testjob", "zone", "aa").Active(2.2),
 	)
 
 	at.Run()
diff --git a/test/collector.go b/test/collector.go
index 6f7fb53f..6b9d91c6 100644
--- a/test/collector.go
+++ b/test/collector.go
@@ -2,7 +2,6 @@ package test
 
 import (
 	"fmt"
-	"sort"
 	"testing"
 	"time"
 
@@ -29,12 +28,15 @@ func batchesEqual(as, bs model.Alerts, opts *AcceptanceOpts) bool {
 		return false
 	}
 
-	// Ensure sorting.
-	sort.Sort(as)
-	sort.Sort(bs)
-
-	for i, a := range as {
-		if !equalAlerts(a, bs[i], opts) {
+	for _, a := range as {
+		found := false
+		for _, b := range bs {
+			if equalAlerts(a, b, opts) {
+				found = true
+				break
+			}
+		}
+		if !found {
 			return false
 		}
 	}
@@ -83,7 +85,7 @@ func (c *Collector) check() string {
 			report += fmt.Sprintf("---\n")
 
 			for _, e := range exp {
-				report += fmt.Sprintf("- %v\n", e)
+				report += fmt.Sprintf("- %v\n", c.opts.alertString(e))
 			}
 
 			for at, got := range c.collected {
@@ -137,7 +139,7 @@ func (c *Collector) check() string {
 			for _, alerts := range col {
 				report += fmt.Sprintf("@ %v\n", at)
 				for _, a := range alerts {
-					report += fmt.Sprintf("- %v\n", a)
+					report += fmt.Sprintf("- %v\n", c.opts.alertString(a))
 				}
 			}
 		}