diff --git a/include/asterisk/astmm.h b/include/asterisk/astmm.h
index 26273c9389..cf12f252a2 100644
--- a/include/asterisk/astmm.h
+++ b/include/asterisk/astmm.h
@@ -18,6 +18,9 @@
 
 /*! \file
  * \brief Asterisk memory usage debugging
+ * This file provides headers for MALLOC_DEBUG, a define used for tracking down
+ * memory leaks.  It should never be #included directly; always use the
+ * MALLOC_DEBUG definition in menuselect to activate those functions.
  */