diff --git a/modules/messenger/cmd/messenger/bus_test.go b/modules/messenger/cmd/messenger/bus_test.go
index dc6ada66..6e34d5eb 100644
--- a/modules/messenger/cmd/messenger/bus_test.go
+++ b/modules/messenger/cmd/messenger/bus_test.go
@@ -35,6 +35,7 @@ func TestMain(m *testing.M) {
 	if os.Getenv(bundleVar) == "1" {
 		kindsEvery = 200 * time.Millisecond
 		StartGrace = 500 * time.Millisecond
+		BurstWindow = 200 * time.Millisecond
 		main()
 		os.Exit(0)
 	}
diff --git a/modules/messenger/cmd/messenger/holder.go b/modules/messenger/cmd/messenger/holder.go
index 9afc0e30..79cbb1b8 100644
--- a/modules/messenger/cmd/messenger/holder.go
+++ b/modules/messenger/cmd/messenger/holder.go
@@ -55,6 +55,10 @@ import (
 	"time"
 )
 
+// BurstWindow: what arrives for a channel within it goes out as one message. A variable, so the test bundle
+// shortens it.
+var BurstWindow = 30 * time.Second
+
 // StartGrace: after start, nothing but the urgent conditions open in the controller's state. A variable, as
 // kindsEvery is, so the test bundle shortens it.
 var StartGrace = time.Minute
@@ -75,8 +79,6 @@ const (
 
 	// FreshFor: an event older than this by its own time is history — state, never a message.
 	FreshFor = 10 * time.Minute
-	// BurstWindow: what arrives for a channel within it goes out as one message.
-	BurstWindow = 30 * time.Second
 	// DesktopWarningEvery: warnings reach the desktop at most this often.
 	DesktopWarningEvery = 15 * time.Minute
 	// ResyncEvery: how often the open set is read from the controller again.