diff --git a/README.md b/README.md
index 50f5eee..7469f3e 100644
--- a/README.md
+++ b/README.md
@@ -550,6 +550,11 @@ Here are a few things to note when evaluating and using Bolt:
   However, this is expected and the OS will release memory as needed. Bolt can
   handle databases much larger than the available physical RAM.
 
+* The data structures in the Bolt database are memory mapped so the data file
+  will be endian specific. This means that you cannot copy a Bolt file from a
+  little endian machine to a big endian machine and have it work. For most 
+  users this is not a concern since most modern CPUs are little endian.
+
 * Because of the way pages are laid out on disk, Bolt cannot truncate data files
   and return free pages back to the disk. Instead, Bolt maintains a free list
   of unused pages within its data file. These free pages can be reused by later