diff --git a/README b/README
index d9526ea..fb62501 100644
--- a/README
+++ b/README
@@ -25,5 +25,10 @@ See crypto/compat for the bulk of the local compatibility code.
 It will likely build on any reasonably modern version of Linux, Solaris,
 or OSX with a sane compiler and C library.
 
+Note: Our policy is generally to use your system provided intrinsics.
+If your system provides security sensitive functions (such as
+arc4random(), issetugid(), getentropy(), and others) we will
+assume they are implemented correctly and securely. If they are
+not please contact your OS provider.