diff --git a/src/internal/synctest/synctest_test.go b/src/internal/synctest/synctest_test.go
index c2f84be736..fe6eb63702 100644
--- a/src/internal/synctest/synctest_test.go
+++ b/src/internal/synctest/synctest_test.go
@@ -488,7 +488,7 @@ func TestDeadlockRoot(t *testing.T) {
 }
 
 func TestDeadlockChild(t *testing.T) {
-	defer wantPanic(t, "deadlock: all goroutines in bubble are blocked")
+	defer wantPanic(t, "deadlock: main bubble goroutine has exited but blocked goroutines remain")
 	synctest.Run(func() {
 		go func() {
 			select {}
@@ -497,7 +497,7 @@ func TestDeadlockChild(t *testing.T) {
 }
 
 func TestDeadlockTicker(t *testing.T) {
-	defer wantPanic(t, "deadlock: all goroutines in bubble are blocked")
+	defer wantPanic(t, "deadlock: main bubble goroutine has exited but blocked goroutines remain")
 	synctest.Run(func() {
 		go func() {
 			for range time.Tick(1 * time.Second) {
diff --git a/src/runtime/synctest.go b/src/runtime/synctest.go
index c837c792a5..08a0e5d444 100644
--- a/src/runtime/synctest.go
+++ b/src/runtime/synctest.go
@@ -242,7 +242,13 @@ func synctestRun(f func()) {
 		raceacquireg(gp, gp.bubble.raceaddr())
 	}
 	if total != 1 {
-		panic(synctestDeadlockError{bubble})
+		var reason string
+		if bubble.done {
+			reason = "deadlock: main bubble goroutine has exited but blocked goroutines remain"
+		} else {
+			reason = "deadlock: all goroutines in bubble are blocked"
+		}
+		panic(synctestDeadlockError{reason: reason, bubble: bubble})
 	}
 	if gp.timer != nil && gp.timer.isFake {
 		// Verify that we haven't marked this goroutine's sleep timer as fake.
@@ -252,11 +258,12 @@ func synctestRun(f func()) {
 }
 
 type synctestDeadlockError struct {
+	reason string
 	bubble *synctestBubble
 }
 
-func (synctestDeadlockError) Error() string {
-	return "deadlock: all goroutines in bubble are blocked"
+func (e synctestDeadlockError) Error() string {
+	return e.reason
 }
 
 func synctestidle_c(gp *g, _ unsafe.Pointer) bool {