diff --git a/src/pkg/runtime/proc.c b/src/pkg/runtime/proc.c
index da2e0f9fa4..914a02e0bf 100644
--- a/src/pkg/runtime/proc.c
+++ b/src/pkg/runtime/proc.c
@@ -1459,6 +1459,12 @@ goexit0(G *gp)
 	gp->m = nil;
 	gp->lockedm = nil;
 	gp->paniconfault = 0;
+	gp->defer = nil; // should be true already but just in case.
+	gp->panic = nil; // non-nil for Goexit during panic. points at stack-allocated data.
+	gp->writenbuf = 0;
+	gp->writebuf = nil;
+	gp->waitreason = nil;
+	gp->param = nil;
 	m->curg = nil;
 	m->lockedg = nil;
 	if(m->locked & ~LockExternal) {
diff --git a/test/fixedbugs/issue8158.go b/test/fixedbugs/issue8158.go
new file mode 100644
index 0000000000..b110de11f4
--- /dev/null
+++ b/test/fixedbugs/issue8158.go
@@ -0,0 +1,41 @@
+// run
+
+// Copyright 2014 The Go Authors.  All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package main
+
+import (
+	"runtime"
+	"time"
+)
+
+func main() {
+	c := make(chan bool, 1)
+	go f1(c)
+	<-c
+	time.Sleep(10 * time.Millisecond)
+	go f2(c)
+	<-c
+}
+
+func f1(done chan bool) {
+	defer func() {
+		recover()
+		done <- true
+		runtime.Goexit() // left stack-allocated Panic struct on gp->panic stack
+	}()
+	panic("p")
+}
+
+func f2(done chan bool) {
+	defer func() {
+		recover()
+		done <- true
+		runtime.Goexit()
+	}()
+	time.Sleep(10 * time.Millisecond) // overwrote Panic struct with Timer struct
+	runtime.GC()                      // walked gp->panic list, found mangled Panic struct, crashed
+	panic("p")
+}