diff --git a/aos/common/queue_testutils.h b/aos/common/queue_testutils.h
index aabdd2d..2d26262 100644
--- a/aos/common/queue_testutils.h
+++ b/aos/common/queue_testutils.h
@@ -1,11 +1,20 @@
-#include "aos/common/queue.h"
+#ifndef AOS_COMMON_QUEUE_TESTUTILS_H_
+#define AOS_COMMON_QUEUE_TESTUTILS_H_
+
+#include "aos/atom_code/ipc_lib/shared_mem.h"
+
+// This file has some general helper functions for dealing with testing things
+// that use shared memory etc.
 
 namespace aos {
 namespace common {
 namespace testing {
 
+// Manages creating and cleaning up "shared memory" which works within this
+// process and any that it fork(2)s.
 class GlobalCoreInstance {
  public:
+  // Calls EnableTestLogging().
   GlobalCoreInstance();
   ~GlobalCoreInstance();
 
@@ -20,6 +29,14 @@
 // initialized), however it can be called more than that.
 void EnableTestLogging();
 
+// Registers an exit handler (using atexit(3)) which will call _exit(2).
+// Intended to be called in a freshly fork(2)ed process where it will run before
+// any other exit handlers that were already registered and prevent them from
+// being run.
+void PreventExit();
+
 }  // namespace testing
 }  // namespace common
 }  // namespace aos
+
+#endif  // AOS_COMMON_QUEUE_TESTUTILS_H_