diff --git a/src/pkg/runtime/mprof.go b/src/pkg/runtime/mprof.go
index 95ea1297edd..5d77c5629c2 100644
--- a/src/pkg/runtime/mprof.go
+++ b/src/pkg/runtime/mprof.go
@@ -164,6 +164,7 @@ func Stack(buf []byte, all bool) int {
 	if len(buf) > 0 {
 		gp.writebuf = &buf[0]
 		gp.writenbuf = int32(len(buf))
+		goroutineheader(gp)
 		traceback(pc, sp, 0, gp)
 		if all {
 			tracebackothers(gp)
diff --git a/src/pkg/runtime/stubs.go b/src/pkg/runtime/stubs.go
index 5f396aa0096..52d0c0e3a56 100644
--- a/src/pkg/runtime/stubs.go
+++ b/src/pkg/runtime/stubs.go
@@ -216,6 +216,7 @@ func gonotetsleepg(n *note, t int64) {
 
 func exitsyscall()
 
+func goroutineheader(gp *g)
 func traceback(pc, sp, lr uintptr, gp *g)
 func tracebackothers(gp *g)