diff --git a/klibc/README b/klibc/README
index 8d5c7e5..4032f55 100644
--- a/klibc/README
+++ b/klibc/README
@@ -17,7 +17,8 @@
    architecture you're compiling for.
 
 c) Change ARCH and OPTFLAGS in the main Makefile to match your
-   architecture.
+   architecture.  If you're cross-compiling, set CROSS to your
+   toolchain prefix.
 
 d) Type "make" and pray...