diff --git a/src/cmd/trace/trace.go b/src/cmd/trace/trace.go
index d986b71f79e0a1..676b9ffa5ab6bc 100644
--- a/src/cmd/trace/trace.go
+++ b/src/cmd/trace/trace.go
@@ -685,13 +685,14 @@ func generateTrace(params *traceParams, consumer traceConsumer) error {
 			}
 			ctx.emitSlice(&fakeMarkStart, text)
 		case trace.EvGCSweepStart:
-			slice := ctx.emitSlice(ev, "SWEEP")
+			slice := ctx.makeSlice(ev, "SWEEP")
 			if done := ev.Link; done != nil && done.Args[0] != 0 {
 				slice.Arg = struct {
 					Swept     uint64 `json:"Swept bytes"`
 					Reclaimed uint64 `json:"Reclaimed bytes"`
 				}{done.Args[0], done.Args[1]}
 			}
+			ctx.emit(slice)
 		case trace.EvGoStart, trace.EvGoStartLabel:
 			info := getGInfo(ev.G)
 			if ev.Type == trace.EvGoStartLabel {
@@ -846,7 +847,11 @@ func (ctx *traceContext) proc(ev *trace.Event) uint64 {
 	}
 }
 
-func (ctx *traceContext) emitSlice(ev *trace.Event, name string) *ViewerEvent {
+func (ctx *traceContext) emitSlice(ev *trace.Event, name string) {
+	ctx.emit(ctx.makeSlice(ev, name))
+}
+
+func (ctx *traceContext) makeSlice(ev *trace.Event, name string) *ViewerEvent {
 	// If ViewerEvent.Dur is not a positive value,
 	// trace viewer handles it as a non-terminating time interval.
 	// Avoid it by setting the field with a small value.
@@ -885,7 +890,6 @@ func (ctx *traceContext) emitSlice(ev *trace.Event, name string) *ViewerEvent {
 			sl.Cname = colorLightGrey
 		}
 	}
-	ctx.emit(sl)
 	return sl
 }