diff --git a/src/runtime/crash_test.go b/src/runtime/crash_test.go
index 843b415006..9f11aea4e9 100644
--- a/src/runtime/crash_test.go
+++ b/src/runtime/crash_test.go
@@ -654,3 +654,33 @@ func TestAbort(t *testing.T) {
 		}
 	}
 }
+
+// For TestRuntimePanic: test a panic in the runtime package without
+// involving the testing harness.
+func init() {
+	if os.Getenv("GO_TEST_RUNTIME_PANIC") == "1" {
+		defer func() {
+			if r := recover(); r != nil {
+				// We expect to crash, so exit 0
+				// to indicate failure.
+				os.Exit(0)
+			}
+		}()
+		runtime.PanicForTesting(nil, 1)
+		// We expect to crash, so exit 0 to indicate failure.
+		os.Exit(0)
+	}
+}
+
+func TestRuntimePanic(t *testing.T) {
+	testenv.MustHaveExec(t)
+	cmd := exec.Command(os.Args[0], "-test.run=TestRuntimePanic")
+	cmd.Env = append(cmd.Env, "GO_TEST_RUNTIME_PANIC=1")
+	out, err := cmd.CombinedOutput()
+	t.Logf("%s", out)
+	if err == nil {
+		t.Error("child process did not fail")
+	} else if want := "runtime.unexportedPanicForTesting"; !bytes.Contains(out, []byte(want)) {
+		t.Errorf("output did not contain expected string %q", want)
+	}
+}
diff --git a/src/runtime/export_test.go b/src/runtime/export_test.go
index b21179cc8c..7ebdfc1520 100644
--- a/src/runtime/export_test.go
+++ b/src/runtime/export_test.go
@@ -451,3 +451,13 @@ type G = g
 func Getg() *G {
 	return getg()
 }
+
+//go:noinline
+func PanicForTesting(b []byte, i int) byte {
+	return unexportedPanicForTesting(b, i)
+}
+
+//go:noinline
+func unexportedPanicForTesting(b []byte, i int) byte {
+	return b[i]
+}
diff --git a/src/runtime/panic.go b/src/runtime/panic.go
index ce367cfa70..7bb7f9b90c 100644
--- a/src/runtime/panic.go
+++ b/src/runtime/panic.go
@@ -23,7 +23,23 @@ func panicCheckMalloc(err error) {
 
 var indexError = error(errorString("index out of range"))
 
+// The panicindex, panicslice, and panicdivide functions are called by
+// code generated by the compiler for out of bounds index expressions,
+// out of bounds slice expressions, and division by zero. The
+// panicdivide (again), panicoverflow, panicfloat, and panicmem
+// functions are called by the signal handler when a signal occurs
+// indicating the respective problem.
+//
+// Since panicindex and panicslice are never called directly, and
+// since the runtime package should never have an out of bounds slice
+// or array reference, if we see those functions called from the
+// runtime package we turn the panic into a throw. That will dump the
+// entire runtime stack for easier debugging.
+
 func panicindex() {
+	if hasprefix(funcname(findfunc(getcallerpc())), "runtime.") {
+		throw(string(indexError.(errorString)))
+	}
 	panicCheckMalloc(indexError)
 	panic(indexError)
 }
@@ -31,6 +47,9 @@ func panicindex() {
 var sliceError = error(errorString("slice bounds out of range"))
 
 func panicslice() {
+	if hasprefix(funcname(findfunc(getcallerpc())), "runtime.") {
+		throw(string(sliceError.(errorString)))
+	}
 	panicCheckMalloc(sliceError)
 	panic(sliceError)
 }